This example is taken from Example 126.2 in ChapterĀ 126, The TRANSREG Procedure. The following statements create a SAS data set that contains failure times for yarn:
proc format;
value a -1 = 8 0 = 9 1 = 10;
value l -1 = 250 0 = 300 1 = 350;
value o -1 = 40 0 = 45 1 = 50;
run;
data yarn;
input Fail Amplitude Length Load @@;
format amplitude a. length l. load o.;
label fail = 'Time in Cycles until Failure';
datalines;
674 -1 -1 -1 370 -1 -1 0 292 -1 -1 1 338 0 -1 -1
266 0 -1 0 210 0 -1 1 170 1 -1 -1 118 1 -1 0
... more lines ...
;
The following statements run PROC TRANSREG:
proc transreg data=yarn;
model BoxCox(fail / convenient lambda=-2 to 2 by 0.05) =
qpoint(length amplitude load);
run;
The log-likelihood plot in FigureĀ 9 suggests a Box-Cox transformation where .
Figure 9: Box-Cox "Significant Effects"
