simple model fitting using R

x=c(0,1,2,3,4)y=c(1,2,3,4,5)r=nls(y ~ 1/(1+4*x*p),start=list(p=0))summary(r)xt=seq(1,1000,0.1)yt=1/(1+4*xt*0.02860)postscript(file="/path/to/directory/test.ps",width=7,height=7)or svg(file="/path/to/directory/test.svg",width=7,height=7)plot(xt,yt,'l',xlab="xlabel",ylab="ylabel")points(x,y)dev.off()

读tab分隔的txt:

a=read.table(file="x.txt",header=FALSE);
c=a[2:255,2];      读第2列, 从第2行到第255行
s=sum(as.numeric(c))
d=c/s;
x=a[2:255,1];      读第1列, 从第2行到第255行
y=d*100;
postscript(file="x.ps",width=7,height=7)  
xt=x[4:100]
yt=y[4:100]
plot(xt,yt,'l',xlab="Depth",ylab="Percent")  
points(xt,yt)  
dev.off()