tests/testthat/_snaps/stepaic-f-output.md

output from stepAIC forward regression is as expected

Code
  ols_step_forward_aic(model)
Output


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_aic(model, progress = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. pindex 
  3. enzyme_test 
  4. liver_test 
  5. age 
  6. gender 
  7. alc_mod 
  8. alc_heavy


  Variables Entered:

  => liver_test 
  => alc_heavy 
  => enzyme_test 
  => pindex 
  => bcs

  No more variables to be added.


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_aic(model, details = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. pindex 
  3. enzyme_test 
  4. liver_test 
  5. age 
  6. gender 
  7. alc_mod 
  8. alc_heavy


  Step     => 0 
  Model    => y ~ 1 
  AIC      => 802.606

  Initiating stepwise selection...

                         Table: Adding New Variables                        
  -------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2  
  -------------------------------------------------------------------------
  liver_test      1    771.875    777.842    616.009    0.45454     0.44405 
  enzyme_test     1    782.629    788.596    626.220    0.33435     0.32154 
  pindex          1    794.100    800.067    637.196    0.17680     0.16097 
  alc_heavy       1    794.301    800.268    637.389    0.17373     0.15784 
  bcs             1    797.697    803.664    640.655    0.12010     0.10318 
  alc_mod         1    802.828    808.795    645.601    0.03239     0.01378 
  gender          1    802.956    808.923    645.725    0.03009     0.01143 
  age             1    803.834    809.801    646.572    0.01420    -0.00476 
  -------------------------------------------------------------------------

  Step     => 1 
  Added    => liver_test 
  Model    => y ~ liver_test 
  AIC      => 771.8753

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  alc_heavy       1    761.439    769.395    605.506    0.56674    0.54975 
  enzyme_test     1    762.077    770.033    606.090    0.56159    0.54440 
  pindex          1    770.387    778.343    613.737    0.48866    0.46861 
  alc_mod         1    771.141    779.097    614.435    0.48147    0.46113 
  gender          1    773.802    781.758    616.901    0.45528    0.43391 
  age             1    773.831    781.787    616.928    0.45498    0.43361 
  bcs             1    773.867    781.823    616.961    0.45462    0.43323 
  ------------------------------------------------------------------------

  Step     => 2 
  Added    => alc_heavy 
  Model    => y ~ liver_test + alc_heavy 
  AIC      => 761.4394

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  enzyme_test     1    750.509    760.454    595.297    0.65900    0.63854 
  pindex          1    756.125    766.070    600.225    0.62163    0.59892 
  bcs             1    763.063    773.008    606.379    0.56975    0.54394 
  age             1    763.110    773.055    606.421    0.56938    0.54354 
  alc_mod         1    763.428    773.373    606.704    0.56683    0.54084 
  gender          1    763.433    773.378    606.709    0.56679    0.54080 
  ------------------------------------------------------------------------

  Step     => 3 
  Added    => enzyme_test 
  Model    => y ~ liver_test + alc_heavy + enzyme_test 
  AIC      => 750.5089

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  pindex        1    735.715    747.649    582.943    0.75015    0.72975 
  bcs           1    750.782    762.716    595.377    0.66973    0.64277 
  alc_mod       1    752.403    764.337    596.743    0.65967    0.63189 
  age           1    752.416    764.350    596.755    0.65959    0.63180 
  gender        1    752.509    764.443    596.833    0.65900    0.63116 
  ----------------------------------------------------------------------

  Step     => 4 
  Added    => pindex 
  Model    => y ~ liver_test + alc_heavy + enzyme_test + pindex 
  AIC      => 735.7146

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  bcs           1    730.620    744.543    579.638    0.78091    0.75808 
  age           1    737.680    751.603    585.012    0.75030    0.72429 
  gender        1    737.712    751.635    585.036    0.75016    0.72413 
  alc_mod       1    737.713    751.636    585.037    0.75015    0.72413 
  ----------------------------------------------------------------------

  Step     => 5 
  Added    => bcs 
  Model    => y ~ liver_test + alc_heavy + enzyme_test + pindex + bcs 
  AIC      => 730.6204

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  age           1    732.494    748.406    581.938    0.78142    0.75351 
  gender        1    732.551    748.463    581.978    0.78119    0.75325 
  alc_mod       1    732.614    748.526    582.023    0.78093    0.75297 
  ----------------------------------------------------------------------


  No more variables to be added.

  Variables Selected:

  => liver_test 
  => alc_heavy 
  => enzyme_test 
  => pindex 
  => bcs


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_aic(model, include = "pindex", details = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. enzyme_test 
  3. liver_test 
  4. age 
  5. gender 
  6. alc_mod 
  7. alc_heavy


  Step     => 0 
  Model    => y ~ pindex 
  AIC      => 794.0997

  Initiating stepwise selection...

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  enzyme_test     1    766.642    774.598    610.282    0.52292    0.50421 
  liver_test      1    770.387    778.343    613.737    0.48866    0.46861 
  alc_heavy       1    780.568    788.524    623.203    0.38256    0.35835 
  bcs             1    789.400    797.356    631.496    0.27285    0.24434 
  alc_mod         1    792.349    800.305    634.280    0.23204    0.20192 
  gender          1    795.111    803.067    636.895    0.19174    0.16004 
  age             1    795.450    803.406    637.216    0.18665    0.15476 
  ------------------------------------------------------------------------

  Step     => 1 
  Added    => enzyme_test 
  Model    => y ~ pindex + enzyme_test 
  AIC      => 766.6422

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  bcs            1    746.376    756.320    591.702    0.68413    0.66518 
  alc_heavy      1    748.167    758.112    593.257    0.67347    0.65388 
  liver_test     1    755.099    765.044    599.321    0.62875    0.60647 
  alc_mod        1    764.533    774.477    607.692    0.55788    0.53135 
  age            1    767.697    777.642    610.529    0.53120    0.50307 
  gender         1    768.479    778.424    611.232    0.52436    0.49582 
  -----------------------------------------------------------------------

  Step     => 2 
  Added    => bcs 
  Model    => y ~ pindex + enzyme_test + bcs 
  AIC      => 746.3755

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  alc_heavy      1    730.924    742.858    579.087    0.77136    0.75269 
  alc_mod        1    744.985    756.919    590.537    0.70335    0.67913 
  age            1    747.171    759.105    592.354    0.69109    0.66588 
  liver_test     1    747.181    759.114    592.362    0.69104    0.66582 
  gender         1    748.330    760.264    593.322    0.68439    0.65863 
  -----------------------------------------------------------------------

  Step     => 3 
  Added    => alc_heavy 
  Model    => y ~ pindex + enzyme_test + bcs + alc_heavy 
  AIC      => 730.9241

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  liver_test     1    730.620    744.543    579.638    0.78091    0.75808 
  age            1    732.339    746.262    580.934    0.77382    0.75026 
  gender         1    732.516    746.439    581.067    0.77308    0.74944 
  alc_mod        1    732.909    746.832    581.365    0.77142    0.74761 
  -----------------------------------------------------------------------

  Step     => 4 
  Added    => liver_test 
  Model    => y ~ pindex + enzyme_test + bcs + alc_heavy + liver_test 
  AIC      => 730.6204

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  age           1    732.494    748.406    581.938    0.78142    0.75351 
  gender        1    732.551    748.463    581.978    0.78119    0.75325 
  alc_mod       1    732.614    748.526    582.023    0.78093    0.75297 
  ----------------------------------------------------------------------


  No more variables to be added.

  Variables Selected:

  => pindex 
  => enzyme_test 
  => bcs 
  => alc_heavy 
  => liver_test


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     794.100    800.067    637.196    0.17680    0.16097 
   1      enzyme_test    766.642    774.598    610.282    0.52292    0.50421 
   2      bcs            746.376    756.320    591.702    0.68413    0.66518 
   3      alc_heavy      730.924    742.858    579.087    0.77136    0.75269 
   4      liver_test     730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
  ------------------------------------------------------------------------------------------------

output from stepSBC forward regression is as expected

Code
  ols_step_forward_sbc(model)
Output


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_sbc(model, progress = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. pindex 
  3. enzyme_test 
  4. liver_test 
  5. age 
  6. gender 
  7. alc_mod 
  8. alc_heavy


  Variables Entered:

  => liver_test 
  => alc_heavy 
  => enzyme_test 
  => pindex 
  => bcs

  No more variables to be added.


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_sbc(model, details = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. pindex 
  3. enzyme_test 
  4. liver_test 
  5. age 
  6. gender 
  7. alc_mod 
  8. alc_heavy


  Step     => 0 
  Model    => y ~ 1 
  SBC      => 806.584

  Initiating stepwise selection...

                         Table: Adding New Variables                        
  -------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2  
  -------------------------------------------------------------------------
  liver_test      1    771.875    777.842    616.009    0.45454     0.44405 
  enzyme_test     1    782.629    788.596    626.220    0.33435     0.32154 
  pindex          1    794.100    800.067    637.196    0.17680     0.16097 
  alc_heavy       1    794.301    800.268    637.389    0.17373     0.15784 
  bcs             1    797.697    803.664    640.655    0.12010     0.10318 
  alc_mod         1    802.828    808.795    645.601    0.03239     0.01378 
  gender          1    802.956    808.923    645.725    0.03009     0.01143 
  age             1    803.834    809.801    646.572    0.01420    -0.00476 
  -------------------------------------------------------------------------

  Step     => 1 
  Added    => liver_test 
  Model    => y ~ liver_test 
  SBC      => 777.8423

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  alc_heavy       1    761.439    769.395    605.506    0.56674    0.54975 
  enzyme_test     1    762.077    770.033    606.090    0.56159    0.54440 
  pindex          1    770.387    778.343    613.737    0.48866    0.46861 
  alc_mod         1    771.141    779.097    614.435    0.48147    0.46113 
  gender          1    773.802    781.758    616.901    0.45528    0.43391 
  age             1    773.831    781.787    616.928    0.45498    0.43361 
  bcs             1    773.867    781.823    616.961    0.45462    0.43323 
  ------------------------------------------------------------------------

  Step     => 2 
  Added    => alc_heavy 
  Model    => y ~ liver_test + alc_heavy 
  SBC      => 769.3953

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  enzyme_test     1    750.509    760.454    595.297    0.65900    0.63854 
  pindex          1    756.125    766.070    600.225    0.62163    0.59892 
  bcs             1    763.063    773.008    606.379    0.56975    0.54394 
  age             1    763.110    773.055    606.421    0.56938    0.54354 
  alc_mod         1    763.428    773.373    606.704    0.56683    0.54084 
  gender          1    763.433    773.378    606.709    0.56679    0.54080 
  ------------------------------------------------------------------------

  Step     => 3 
  Added    => enzyme_test 
  Model    => y ~ liver_test + alc_heavy + enzyme_test 
  SBC      => 760.4538

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  pindex        1    735.715    747.649    582.943    0.75015    0.72975 
  bcs           1    750.782    762.716    595.377    0.66973    0.64277 
  alc_mod       1    752.403    764.337    596.743    0.65967    0.63189 
  age           1    752.416    764.350    596.755    0.65959    0.63180 
  gender        1    752.509    764.443    596.833    0.65900    0.63116 
  ----------------------------------------------------------------------

  Step     => 4 
  Added    => pindex 
  Model    => y ~ liver_test + alc_heavy + enzyme_test + pindex 
  SBC      => 747.6485

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  bcs           1    730.620    744.543    579.638    0.78091    0.75808 
  age           1    737.680    751.603    585.012    0.75030    0.72429 
  gender        1    737.712    751.635    585.036    0.75016    0.72413 
  alc_mod       1    737.713    751.636    585.037    0.75015    0.72413 
  ----------------------------------------------------------------------

  Step     => 5 
  Added    => bcs 
  Model    => y ~ liver_test + alc_heavy + enzyme_test + pindex + bcs 
  SBC      => 744.5433

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  age           1    732.494    748.406    581.938    0.78142    0.75351 
  gender        1    732.551    748.463    581.978    0.78119    0.75325 
  alc_mod       1    732.614    748.526    582.023    0.78093    0.75297 
  ----------------------------------------------------------------------


  No more variables to be added.

  Variables Selected:

  => liver_test 
  => alc_heavy 
  => enzyme_test 
  => pindex 
  => bcs


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_sbc(model, include = "pindex", details = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. enzyme_test 
  3. liver_test 
  4. age 
  5. gender 
  6. alc_mod 
  7. alc_heavy


  Step     => 0 
  Model    => y ~ pindex 
  SBC      => 800.0667

  Initiating stepwise selection...

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  enzyme_test     1    766.642    774.598    610.282    0.52292    0.50421 
  liver_test      1    770.387    778.343    613.737    0.48866    0.46861 
  alc_heavy       1    780.568    788.524    623.203    0.38256    0.35835 
  bcs             1    789.400    797.356    631.496    0.27285    0.24434 
  alc_mod         1    792.349    800.305    634.280    0.23204    0.20192 
  gender          1    795.111    803.067    636.895    0.19174    0.16004 
  age             1    795.450    803.406    637.216    0.18665    0.15476 
  ------------------------------------------------------------------------

  Step     => 1 
  Added    => enzyme_test 
  Model    => y ~ pindex + enzyme_test 
  SBC      => 774.5982

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  bcs            1    746.376    756.320    591.702    0.68413    0.66518 
  alc_heavy      1    748.167    758.112    593.257    0.67347    0.65388 
  liver_test     1    755.099    765.044    599.321    0.62875    0.60647 
  alc_mod        1    764.533    774.477    607.692    0.55788    0.53135 
  age            1    767.697    777.642    610.529    0.53120    0.50307 
  gender         1    768.479    778.424    611.232    0.52436    0.49582 
  -----------------------------------------------------------------------

  Step     => 2 
  Added    => bcs 
  Model    => y ~ pindex + enzyme_test + bcs 
  SBC      => 756.3204

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  alc_heavy      1    730.924    742.858    579.087    0.77136    0.75269 
  alc_mod        1    744.985    756.919    590.537    0.70335    0.67913 
  age            1    747.171    759.105    592.354    0.69109    0.66588 
  liver_test     1    747.181    759.114    592.362    0.69104    0.66582 
  gender         1    748.330    760.264    593.322    0.68439    0.65863 
  -----------------------------------------------------------------------

  Step     => 3 
  Added    => alc_heavy 
  Model    => y ~ pindex + enzyme_test + bcs + alc_heavy 
  SBC      => 742.858

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  liver_test     1    730.620    744.543    579.638    0.78091    0.75808 
  age            1    732.339    746.262    580.934    0.77382    0.75026 
  gender         1    732.516    746.439    581.067    0.77308    0.74944 
  alc_mod        1    732.909    746.832    581.365    0.77142    0.74761 
  -----------------------------------------------------------------------


  No more variables to be added.

  Variables Selected:

  => pindex 
  => enzyme_test 
  => bcs 
  => alc_heavy


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     794.100    800.067    637.196    0.17680    0.16097 
   1      enzyme_test    766.642    774.598    610.282    0.52292    0.50421 
   2      bcs            746.376    756.320    591.702    0.68413    0.66518 
   3      alc_heavy      730.924    742.858    579.087    0.77136    0.75269 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.878       RMSE                 188.249 
  R-Squared                 0.771       MSE                39053.801 
  Adj. R-Squared            0.753       Coef. Var             28.147 
  Pred R-Squared            0.695       AIC                  730.924 
  MAE                     140.619       SBC                  742.858 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6455884.265         4    1613971.066    41.327    0.0000 
  Residual      1913636.272        49      39053.801                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1334.424       180.589                 -7.389    0.000    -1697.332    -971.516 
       pindex       10.131         1.622        0.431     6.246    0.000        6.871      13.390 
  enzyme_test       11.243         1.308        0.601     8.596    0.000        8.614      13.871 
          bcs       81.439        17.781        0.329     4.580    0.000       45.706     117.171 
    alc_heavy      312.777        72.341        0.309     4.324    0.000      167.402     458.152 
  ------------------------------------------------------------------------------------------------

output from stepSBIC forward regression is as expected

Code
  ols_step_forward_sbic(model)
Output


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_sbic(model, progress = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. pindex 
  3. enzyme_test 
  4. liver_test 
  5. age 
  6. gender 
  7. alc_mod 
  8. alc_heavy


  Variables Entered:

  => liver_test 
  => alc_heavy 
  => enzyme_test 
  => pindex 
  => bcs

  No more variables to be added.


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_sbic(model, details = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. pindex 
  3. enzyme_test 
  4. liver_test 
  5. age 
  6. gender 
  7. alc_mod 
  8. alc_heavy


  Step     => 0 
  Model    => y ~ 1 
  SBIC     => 649.3977

  Initiating stepwise selection...

                         Table: Adding New Variables                        
  -------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2  
  -------------------------------------------------------------------------
  liver_test      1    771.875    777.842    616.009    0.45454     0.44405 
  enzyme_test     1    782.629    788.596    626.220    0.33435     0.32154 
  pindex          1    794.100    800.067    637.196    0.17680     0.16097 
  alc_heavy       1    794.301    800.268    637.389    0.17373     0.15784 
  bcs             1    797.697    803.664    640.655    0.12010     0.10318 
  alc_mod         1    802.828    808.795    645.601    0.03239     0.01378 
  gender          1    802.956    808.923    645.725    0.03009     0.01143 
  age             1    803.834    809.801    646.572    0.01420    -0.00476 
  -------------------------------------------------------------------------

  Step     => 1 
  Added    => liver_test 
  Model    => y ~ liver_test 
  SBIC     => 618.7808

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  alc_heavy       1    761.439    769.395    605.506    0.56674    0.54975 
  enzyme_test     1    762.077    770.033    606.090    0.56159    0.54440 
  pindex          1    770.387    778.343    613.737    0.48866    0.46861 
  alc_mod         1    771.141    779.097    614.435    0.48147    0.46113 
  gender          1    773.802    781.758    616.901    0.45528    0.43391 
  age             1    773.831    781.787    616.928    0.45498    0.43361 
  bcs             1    773.867    781.823    616.961    0.45462    0.43323 
  ------------------------------------------------------------------------

  Step     => 2 
  Added    => alc_heavy 
  Model    => y ~ liver_test + alc_heavy 
  SBIC     => 608.54

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  enzyme_test     1    750.509    760.454    595.297    0.65900    0.63854 
  pindex          1    756.125    766.070    600.225    0.62163    0.59892 
  bcs             1    763.063    773.008    606.379    0.56975    0.54394 
  age             1    763.110    773.055    606.421    0.56938    0.54354 
  alc_mod         1    763.428    773.373    606.704    0.56683    0.54084 
  gender          1    763.433    773.378    606.709    0.56679    0.54080 
  ------------------------------------------------------------------------

  Step     => 3 
  Added    => enzyme_test 
  Model    => y ~ liver_test + alc_heavy + enzyme_test 
  SBIC     => 597.8907

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  pindex        1    735.715    747.649    582.943    0.75015    0.72975 
  bcs           1    750.782    762.716    595.377    0.66973    0.64277 
  alc_mod       1    752.403    764.337    596.743    0.65967    0.63189 
  age           1    752.416    764.350    596.755    0.65959    0.63180 
  gender        1    752.509    764.443    596.833    0.65900    0.63116 
  ----------------------------------------------------------------------

  Step     => 4 
  Added    => pindex 
  Model    => y ~ liver_test + alc_heavy + enzyme_test + pindex 
  SBIC     => 583.4688

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  bcs           1    730.620    744.543    579.638    0.78091    0.75808 
  age           1    737.680    751.603    585.012    0.75030    0.72429 
  gender        1    737.712    751.635    585.036    0.75016    0.72413 
  alc_mod       1    737.713    751.636    585.037    0.75015    0.72413 
  ----------------------------------------------------------------------

  Step     => 5 
  Added    => bcs 
  Model    => y ~ liver_test + alc_heavy + enzyme_test + pindex + bcs 
  SBIC     => 578.8438

                       Table: Adding New Variables                       
  ----------------------------------------------------------------------
  Predictor    DF      AIC        SBC       SBIC        R2       Adj. R2 
  ----------------------------------------------------------------------
  age           1    732.494    748.406    581.938    0.78142    0.75351 
  gender        1    732.551    748.463    581.978    0.78119    0.75325 
  alc_mod       1    732.614    748.526    582.023    0.78093    0.75297 
  ----------------------------------------------------------------------


  No more variables to be added.

  Variables Selected:

  => liver_test 
  => alc_heavy 
  => enzyme_test 
  => pindex 
  => bcs


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     802.606    806.584    646.794    0.00000    0.00000 
   1      liver_test     771.875    777.842    616.009    0.45454    0.44405 
   2      alc_heavy      761.439    769.395    605.506    0.56674    0.54975 
   3      enzyme_test    750.509    760.454    595.297    0.65900    0.63854 
   4      pindex         735.715    747.649    582.943    0.75015    0.72975 
   5      bcs            730.620    744.543    579.638    0.78091    0.75808 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.884       RMSE                 184.276 
  R-Squared                 0.781       MSE                38202.426 
  Adj. R-Squared            0.758       Coef. Var             27.839 
  Pred R-Squared            0.700       AIC                  730.620 
  MAE                     137.656       SBC                  744.543 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6535804.090         5    1307160.818    34.217    0.0000 
  Residual      1833716.447        48      38202.426                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1178.330       208.682                 -5.647    0.000    -1597.914    -758.746 
   liver_test       58.064        40.144        0.156     1.446    0.155      -22.652     138.779 
    alc_heavy      317.848        71.634        0.314     4.437    0.000      173.818     461.878 
  enzyme_test        9.748         1.656        0.521     5.887    0.000        6.419      13.077 
       pindex        8.924         1.808        0.380     4.935    0.000        5.288      12.559 
          bcs       59.864        23.060        0.241     2.596    0.012       13.498     106.230 
  ------------------------------------------------------------------------------------------------
Code
  ols_step_forward_sbic(model, include = "pindex", details = TRUE)
Output
  Forward Selection Method 
  ------------------------

  Candidate Terms:

  1. bcs 
  2. enzyme_test 
  3. liver_test 
  4. age 
  5. gender 
  6. alc_mod 
  7. alc_heavy


  Step     => 0 
  Model    => y ~ pindex 
  SBIC     => 641.0052

  Initiating stepwise selection...

                        Table: Adding New Variables                        
  ------------------------------------------------------------------------
  Predictor      DF      AIC        SBC       SBIC        R2       Adj. R2 
  ------------------------------------------------------------------------
  enzyme_test     1    766.642    774.598    610.282    0.52292    0.50421 
  liver_test      1    770.387    778.343    613.737    0.48866    0.46861 
  alc_heavy       1    780.568    788.524    623.203    0.38256    0.35835 
  bcs             1    789.400    797.356    631.496    0.27285    0.24434 
  alc_mod         1    792.349    800.305    634.280    0.23204    0.20192 
  gender          1    795.111    803.067    636.895    0.19174    0.16004 
  age             1    795.450    803.406    637.216    0.18665    0.15476 
  ------------------------------------------------------------------------

  Step     => 1 
  Added    => enzyme_test 
  Model    => y ~ pindex + enzyme_test 
  SBIC     => 613.7429

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  bcs            1    746.376    756.320    591.702    0.68413    0.66518 
  alc_heavy      1    748.167    758.112    593.257    0.67347    0.65388 
  liver_test     1    755.099    765.044    599.321    0.62875    0.60647 
  alc_mod        1    764.533    774.477    607.692    0.55788    0.53135 
  age            1    767.697    777.642    610.529    0.53120    0.50307 
  gender         1    768.479    778.424    611.232    0.52436    0.49582 
  -----------------------------------------------------------------------

  Step     => 2 
  Added    => bcs 
  Model    => y ~ pindex + enzyme_test + bcs 
  SBIC     => 593.7573

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  alc_heavy      1    730.924    742.858    579.087    0.77136    0.75269 
  alc_mod        1    744.985    756.919    590.537    0.70335    0.67913 
  age            1    747.171    759.105    592.354    0.69109    0.66588 
  liver_test     1    747.181    759.114    592.362    0.69104    0.66582 
  gender         1    748.330    760.264    593.322    0.68439    0.65863 
  -----------------------------------------------------------------------

  Step     => 3 
  Added    => alc_heavy 
  Model    => y ~ pindex + enzyme_test + bcs + alc_heavy 
  SBIC     => 578.6783

                        Table: Adding New Variables                       
  -----------------------------------------------------------------------
  Predictor     DF      AIC        SBC       SBIC        R2       Adj. R2 
  -----------------------------------------------------------------------
  liver_test     1    730.620    744.543    579.638    0.78091    0.75808 
  age            1    732.339    746.262    580.934    0.77382    0.75026 
  gender         1    732.516    746.439    581.067    0.77308    0.74944 
  alc_mod        1    732.909    746.832    581.365    0.77142    0.74761 
  -----------------------------------------------------------------------


  No more variables to be added.

  Variables Selected:

  => pindex 
  => enzyme_test 
  => bcs 
  => alc_heavy


                                Stepwise Summary                              
  --------------------------------------------------------------------------
  Step    Variable         AIC        SBC       SBIC        R2       Adj. R2 
  --------------------------------------------------------------------------
   0      Base Model     794.100    800.067    637.196    0.17680    0.16097 
   1      enzyme_test    766.642    774.598    610.282    0.52292    0.50421 
   2      bcs            746.376    756.320    591.702    0.68413    0.66518 
   3      alc_heavy      730.924    742.858    579.087    0.77136    0.75269 
  --------------------------------------------------------------------------

  Final Model Output 
  ------------------

                             Model Summary                            
  -------------------------------------------------------------------
  R                         0.878       RMSE                 188.249 
  R-Squared                 0.771       MSE                39053.801 
  Adj. R-Squared            0.753       Coef. Var             28.147 
  Pred R-Squared            0.695       AIC                  730.924 
  MAE                     140.619       SBC                  742.858 
  -------------------------------------------------------------------
   RMSE: Root Mean Square Error 
   MSE: Mean Square Error 
   MAE: Mean Absolute Error 
   AIC: Akaike Information Criteria 
   SBC: Schwarz Bayesian Criteria

                                   ANOVA                                  
  -----------------------------------------------------------------------
                     Sum of                                              
                    Squares        DF    Mean Square      F         Sig. 
  -----------------------------------------------------------------------
  Regression    6455884.265         4    1613971.066    41.327    0.0000 
  Residual      1913636.272        49      39053.801                     
  Total         8369520.537        53                                    
  -----------------------------------------------------------------------

                                        Parameter Estimates                                        
  ------------------------------------------------------------------------------------------------
        model         Beta    Std. Error    Std. Beta      t        Sig         lower       upper 
  ------------------------------------------------------------------------------------------------
  (Intercept)    -1334.424       180.589                 -7.389    0.000    -1697.332    -971.516 
       pindex       10.131         1.622        0.431     6.246    0.000        6.871      13.390 
  enzyme_test       11.243         1.308        0.601     8.596    0.000        8.614      13.871 
          bcs       81.439        17.781        0.329     4.580    0.000       45.706     117.171 
    alc_heavy      312.777        72.341        0.309     4.324    0.000      167.402     458.152 
  ------------------------------------------------------------------------------------------------


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olsrr documentation built on May 29, 2024, 12:35 p.m.