#1
spec = read.table("M100_spec.txt",header=FALSE)
spec.boolmask = (21 > spec[,2]) & (spec[,2] >17)
spec.zero = spec
spec.notnull = (spec[,2] != 0)
spec.fit <- lm(spec[spec.boolmask,2] ~ spec[spec.boolmask,1])
spec.zero[,2]=(spec[,2])-coef(spec.fit)[1]

#2
y=spec.zero[622:646,2]
x=spec.zero[622:646,1]
gbin <- cbind(spec.zero[622:646,])
Sigma= var(gbin)
mu = apply(gbin,2,mean)
gcoeffs <-nls(y~(b/a)*exp(-(x-6599.2820)^2/(2*a**2)),start=list(a=1,b=200), trace=TRUE)
yg=(231.24/1.73)*exp(-(x-6599.2820)^2/(2*1.73**2))
plot(spec.zero[spec.notNull,1],spec.zero[spec.notNull,2],'l')
lines(x,yg,col='red')