if( !require('investr') ){
    install.packages('investr', dependencies=TRUE, repos='http://cran.rstudio.com/')
}
library(investr) # has the function plotFit

#
# btb data: 
#
load(file='../../BookCode/nlrwr/data/btb.rda')
plot(btb$x, btb$y, xlab='x', ylab='y')
grid()

btb.m1 = nls(y ~ theta1 + (theta2 - theta1)^(theta3 + 1) / (x - theta1)^theta3, data=btb, start=list(theta1=2, theta2=4, theta3=1), trace=FALSE)
print(summary(btb.m1))

#postscript("../../WriteUp/Graphics/Chapter3/chap_3_prob_1_btb.eps", onefile=FALSE, horizontal=FALSE)
plotFit(btb.m1, main='btb data and fit')
grid()
#dev.off()


#
# sts data: 
#
load(file='../../BookCode/nlrwr/data/sts.rda')

plot(sts$x, sts$y, xlab='x', ylab='y')
grid()

sts.m1 = nls(y ~ theta1 + (theta2 - theta1)^(theta3 + 1) / (x - theta1)^theta3, data=sts, start=list(theta1=2, theta2=4, theta3=1), trace=FALSE)
print(summary(sts.m1))

#postscript("../../WriteUp/Graphics/Chapter3/chap_3_prob_1_sts.eps", onefile=FALSE, horizontal=FALSE)
plotFit(sts.m1, main='sts data and fit')
grid()
#dev.off()