Plot lm in a little interval

Question

I am writing a function which plots a linear regression in a subset of my variable.

FitWeibull <- function(data, xinf, xsup){
  xlim <- c(xinf, xsup)
  sub.data <- data
  my.lm <- lm(Y~X, data = sub.data, subset = xlim)
  return(my.lm)
 }

Will this function let me draw my regression between xinf and xsup and keep the other points on the graph?

Answer 1

You need to specify on what variable you are subsetting. Easiest thing is replacing your sub.data <- data line with: sub.data <- data[(X>xinf & X<xsup),], so that you just have

FitWeibull <- function(data, xinf, xsup){
  sub.data <- data[(data$X > xinf & data$X < xsup),]
  my.lm <- lm(Y~X, data = sub.data)
  return(my.lm)
}

You can then do whatever plotting/summarizing you want with the returned object.