##############################################
# HOW TO USE THIS FILE
# This file (ex5wt.R) can just be sourced
# into the R program. But it is really intended to be used interactively
#
######### ANY TEXT AFTER THE # CHARACTER ARE TREATED AS COMMENTS
#
# data stored in c:/GR/aprojects/peas/web/exemp3/data/ex5wt.Rdata
# this file is c:/GR/aprojects/peas/web/exemp3/program_code/ex5wt_R.html
#
##############################################
#
# data are in a data frame data
# to get the names of the variables
#
names(data)
#
# look at the first 5 rows
data[1:5,]
#
# now a logistic regression of response rates
# only the final model is shown here though the other could readily be explored
#
resp<-glm(cbind(AyrA_num,npop)~agegrp+gender+agegrp*agegrp+agegrp*gender+agegrp*agegrp*gender+sinc+sacc+
agegrp*sinc+agegrp*agegrp*sinc,data=data,family=binomial)
print(summary(resp))
#
# we now get the linear predictor
#
lp<-predict(resp)
#
# and make it into a predicted probability
#
phat<-1/(1+exp(-lp))
#
# and get the grossing weight and add to the data frame
#
data$gweight<-1/phat
#
# this can then be merged back to the main file
#