" Exercise 12.4

 Statistical Methods in Biology: Design and Analysis of Experiments and Regression
 by S.J. Welham, S.A. Gezan, S.J. Clark & A. Mead (2014)
 Chapman & Hall/CRC Press, Boca Raton, Florida. ISBN: 978-1-4398-0878-8
 Data from I. Shield, Rothamsted Research
 Version 1, 26/08/2014 "

" Set working directory - change to location of your data file "
\SET [WORKINGDIRECTORY='d:/stats4biol/data/']

" Read data from working directory "
FILEREAD [NAME='WILLOWSTEMS.DAT'; IMETHOD=read] FGROUPS=no

" Plot data "
DGRAPH Y=DryMatter; X=MaxLength

" Fit SLR "
MODEL Y=DryMatter
FIT [FPROBABILITY=yes; TPROBABILITY=yes] MaxLength

" Save fitted values and standardized residuals (see also Exercise 13.5) "
RKEEP FITTEDVALUES=fval; RESIDUALS=res

" Residual plots based on standardized residuals "
DRESIDUALS [RESIDUALS=res; FITTEDVALUES=fval] METHOD=fittedvalues,normal,histogram,absresidual

" Plot fitted SLR"
RGRAPH 

" End of File "