Bond: Strengths of metal bonds

In SASmixed: Data sets from "SAS System for Mixed Models"

Description

The Bond data frame has 21 rows and 3 columns of data on the strength required to break metal bonds according to the metal and the ingot.

Format

This data frame contains the following columns:

pressure

a numeric vector of pressures required to break the bond

Metal

a factor with levels c, i and n indicating the metal involved (copper, iron or nickel).

Ingot

an ordered factor indicating the ingot of the composition material.

Source

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 1.2.4).

Mendenhall, M., Wackerly, D. D. and Schaeffer, R. L. (1990), Mathematical Statistics, Wadsworth (Exercise 13.36).

Examples

str(Bond)
options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
if (require("lme4", quietly = TRUE, character = TRUE)) {
  ## compare with output 1.1 on p. 6
  print(fm1Bond <- lmer(pressure ~ Metal + (1|Ingot), Bond))
  print(anova(fm1Bond))
}

Example output

'data.frame':	21 obs. of  3 variables:
 $ pressure: num  67 71.9 72.2 67.5 68.8 66.4 76 82.6 74.5 72.7 ...
 $ Metal   : Factor w/ 3 levels "c","i","n": 3 2 1 3 2 1 3 2 1 3 ...
 $ Ingot   : Factor w/ 7 levels "1","2","3","4",..: 1 1 1 2 2 2 3 3 3 4 ...
 - attr(*, "ginfo")=List of 7
  ..$ formula     :Class 'formula'  language pressure ~ 1 | Ingot
  .. .. ..- attr(*, ".Environment")=<environment: R_GlobalEnv> 
  ..$ order.groups: logi TRUE
  ..$ FUN         :function (x)  
  ..$ outer       : NULL
  ..$ inner       :Class 'formula'  language ~Metal
  .. .. ..- attr(*, ".Environment")=<environment: R_GlobalEnv> 
  ..$ labels      :List of 1
  .. ..$ pressure: chr "Pressure required to break bond"
  ..$ units       : list()
Linear mixed model fit by REML ['lmerMod']
Formula: pressure ~ Metal + (1 | Ingot)
   Data: Bond
REML criterion at convergence: 107.7902
Random effects:
 Groups   Name        Std.Dev.
 Ingot    (Intercept) 3.383   
 Residual             3.220   
Number of obs: 21, groups:  Ingot, 7
Fixed Effects:
(Intercept)       Metalc       Metali  
    71.1000      -0.9143       4.8000  
Analysis of Variance Table
      Df Sum Sq Mean Sq F value
Metal  2  131.9   65.95  6.3588

SASmixed documentation built on May 1, 2019, 9:18 p.m.