is_simple.Rmd

is = function(sd,nsamp){
x=rnorm(nsamp,0,sd)
w= function(x){x*dnorm(x)/dnorm(x,0,sd)}
return(w(x))
}

w1=is(1,10000)
w2=is(2,10000)
w3 =is(0.1,10000)
w3 =is(20,10000)