[R] Can I build an array of regrssion model?

[Zhongming Yang]

Hi,

I am trying to use piecewise linear regression to approximate a
nonlinear function. Actually, I don't know how many linear functions I
need, therefore, I want build an array of regression models to automate
the approximation job. Could you please give me any clue?

Attached is ongoing code:

rawData = scan("c:/zyang/mass/data/A01/1.PRN",
what=list(numeric(),numeric()));
len = length(rawData[[1]]);
cuts = len*c(0.01, 0.03, 0.08, 0.18, 0.38, 0.69, 1);
cuts = as.integer(cuts); 

mod1 = lm(rawData[[2]][1:cuts[1]]~rawData[[1]][1:cuts[1]]);
mod2 =
lm(rawData[[2]][cuts[1]:cuts[2]]~rawData[[1]][cuts[1]:cuts[2]]);
mod3 =
lm(rawData[[2]][cuts[2]:cuts[3]]~rawData[[1]][cuts[2]:cuts[3]]);
mod4 =
lm(rawData[[2]][cuts[3]:cuts[4]]~rawData[[1]][cuts[3]:cuts[4]]);
mod5 =
lm(rawData[[2]][cuts[4]:cuts[5]]~rawData[[1]][cuts[4]:cuts[5]]);
mod6 =
lm(rawData[[2]][cuts[5]:cuts[6]]~rawData[[1]][cuts[5]:cuts[6]]);
mod7 =
lm(rawData[[2]][cuts[6]:cuts[7]]~rawData[[1]][cuts[6]:cuts[7]]);

plot(rawData[[1]],rawData[[2]],type='l', col="green", xlab="Da/z",
ylab="m/z");
abline(mod1, lty="1", col="red");
abline(mod2, lty="1", col="red");
abline(mod3, lty="1", col="red");
abline(mod4, lty="1", col="red");
abline(mod5, lty="1", col="red");
abline(mod6, lty="1", col="red");
abline(mod7, lty="1", col="red");







Thanks in advance,