Semiconductor: Semiconductor split-plot experiment

Description Format Source Examples

Description

The Semiconductor data frame has 48 rows and 5 columns.

Format

This data frame contains the following columns:

resistance

a numeric vector

ET

a factor with levels 1 to 4 representing etch time.

Wafer

a factor with levels 1 to 3

position

a factor with levels 1 to 4

Grp

an ordered factor with levels 1/1 < 1/2 < 1/3 < 2/1 < 2/2 < 2/3 < 3/1 < 3/2 < 3/3 < 4/1 < 4/2 < 4/3

Source

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 2.2(b)).

Examples

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str(Semiconductor)
if (require("lme4", quietly = TRUE, character = TRUE)) {
  options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
  print(fm1Semi <- lmer(resistance ~ ET * position + (1|Grp), Semiconductor))
  print(anova(fm1Semi))
  print((fm2Semi <- lmer(resistance ~ ET + position + (1|Grp), Semiconductor)))
  print(anova(fm2Semi))
}

Example output

'data.frame':	48 obs. of  5 variables:
 $ resistance: num  5.22 5.61 6.11 6.33 6.13 6.14 5.6 5.91 5.49 4.6 ...
 $ ET        : Factor w/ 4 levels "1","2","3","4": 1 1 1 1 1 1 1 1 1 1 ...
 $ Wafer     : Factor w/ 3 levels "1","2","3": 1 1 1 1 2 2 2 2 3 3 ...
 $ position  : Factor w/ 4 levels "1","2","3","4": 1 2 3 4 1 2 3 4 1 2 ...
 $ Grp       : Factor w/ 12 levels "1/1","1/2","1/3",..: 1 1 1 1 2 2 2 2 3 3 ...
 - attr(*, "ginfo")=List of 7
  ..$ formula     :Class 'formula'  language resistance ~ 1 | Grp
  .. .. ..- attr(*, ".Environment")=<environment: R_GlobalEnv> 
  ..$ order.groups: logi TRUE
  ..$ FUN         :function (x)  
  ..$ outer       :Class 'formula'  language ~ET
  .. .. ..- attr(*, ".Environment")=<environment: R_GlobalEnv> 
  ..$ inner       :Class 'formula'  language ~position
  .. .. ..- attr(*, ".Environment")=<environment: R_GlobalEnv> 
  ..$ labels      : list()
  ..$ units       : list()
Linear mixed model fit by REML ['lmerMod']
Formula: resistance ~ ET * position + (1 | Grp)
   Data: Semiconductor
REML criterion at convergence: 50.6505
Random effects:
 Groups   Name        Std.Dev.
 Grp      (Intercept) 0.3253  
 Residual             0.3334  
Number of obs: 48, groups:  Grp, 12
Fixed Effects:
  (Intercept)            ET1            ET2            ET3      position1  
      6.54000       -0.65333       -0.62333       -0.44667       -0.20000  
    position2      position3  ET1:position1  ET2:position1  ET3:position1  
      0.01333       -0.64333       -0.07333        0.27667        0.24333  
ET1:position2  ET2:position2  ET3:position2  ET1:position3  ET2:position3  
     -0.45000        0.25667        0.24000        0.31000        0.49333  
ET3:position3  
      0.32333  
Analysis of Variance Table
            Df  Sum Sq Mean Sq F value
ET           3 0.64740 0.21580  1.9415
position     3 1.12889 0.37630  3.3855
ET:position  9 0.80947 0.08994  0.8092
Linear mixed model fit by REML ['lmerMod']
Formula: resistance ~ ET + position + (1 | Grp)
   Data: Semiconductor
REML criterion at convergence: 53.0862
Random effects:
 Groups   Name        Std.Dev.
 Grp      (Intercept) 0.3275  
 Residual             0.3246  
Number of obs: 48, groups:  Grp, 12
Fixed Effects:
(Intercept)          ET1          ET2          ET3    position1    position2  
    6.43875     -0.70667     -0.36667     -0.24500     -0.08833      0.02500  
  position3  
   -0.36167  
Analysis of Variance Table
         Df  Sum Sq Mean Sq F value
ET        3 0.61371 0.20457  1.9415
position  3 1.12889 0.37630  3.5714

SASmixed documentation built on May 29, 2017, 12:08 p.m.