" Exercise 12.6

 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 V. Buchanan-Wollaston (PRESTA), University of Warwick
 Version 1, 15/08/2015 "

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

" Read data from working directory "
FILEREAD [NAME='SENESCENCE.DAT'; IMETHOD=read] FGROUPS=2(no),yes,3(no)

" Plot data "
DGRAPH Y=CATMA3A13560; X=Day

" Fit SLR "
MODEL Y=CATMA3A13560
FIT [FPROBABILITY=yes; TPROBABILITY=yes] Day

" Save fitted values and standardized residuals from SLR model "
RKEEP FITTEDVALUES=fitSLR; RESIDUALS=res

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

" Plot fitted model "
RGRAPH 

" Create grouping factor for Day "
GROUPS VECTOR=Day; FACTOR=fDay

" Fit SLR plus lack-of-fit term " 
MODEL Y=CATMA3A13560
FIT [PRINT=#,accumulated; FPROBABILITY=yes; TPROBABILITY=yes] Day+fDay

" Save fitted values from SLR model with LOF "
RKEEP FITTEDVALUES=fitLOF

" Compare fitted values from the two models graphically "
PEN NUMBER=2,3; METHOD=line,point; SYMBOLS=0,2; LINESTYLE=1,0; COLOUR='red','orange'; \
  CFILL=*,'orange'
DGRAPH Y=CATMA3A13560,fitSLR,fitLOF; X=Day; PEN=1...3

" End of File "