lm "weights" argument environment

##a function that makes data and models it
WorksNoweights <- function(){
  someData <- data.frame(x = rnorm(20, 5, 1),y =  1:20 + runif(20),z =  70:51, weight = 0.05)
  print( ls())
  ModObject <- lm('x~y + z', data = someData)
}
WorksNoweights()

##adding a weights argument to lm(...) breaks things
WeightsBreaks <- function(){
  someData <- data.frame(x = rnorm(20, 5, 1),y =  1:20 + runif(20),z =  70:51, weight = 0.05)
  print( ls())
  ModObject <- lm('x~y + z', data = someData, weights = someData$weight)
 }
WeightsBreaks()

##using <<- operator lets the function work
Works <- function(){
  someData <<- data.frame(x = rnorm(20, 5, 1),y =  1:20 + runif(20),z =  70:51, weight = 0.05)
  print( ls())
  ModObject <- lm('x~y + z', data = someData, weights = someData$weight)
}
Works()