Plot a function with several arguments in R

Question

Suppose I want to plot an R function:

weibull <- function(ALPHA, LAMBDA, T){
ALPHA*LAMBDA*(T^(ALPHA-1))
}

So the function takes the arg

Answer 1

If you use curve, you can specify an expression with a free variable x that will get replaced by the range of values specified in your from=/to= parameters. For example you can do

weibull <- function(ALPHA, LAMBDA, T){
    ALPHA*LAMBDA*(T^(ALPHA-1))
}

lambda<-c(1, 2, 4, 8, 16)
col<-rainbow(length(lambda))
layout(matrix(1:2, nrow=1))
for(i in seq_along(lambda)) {
    curve(weibull(.5, lambda[i], x), from=0, to=2, add=i!=1, col=col[i], ylim=c(0,50), main="alpha=.5")
}
legend(1,50,lambda, col=col, lty=1)
for(i in seq_along(lambda)) {
    curve(weibull(1, lambda[i], x), from=0, to=2, add=i!=1, col=col[i], ylim=c(0,20), main="alpha=1")
}

which will produce a plot like