Suppose I want to plot an R function:
weibull <- function(ALPHA, LAMBDA, T){
ALPHA*LAMBDA*(T^(ALPHA-1))
}
So the function takes the arg
This is similar to MrFlick's answer but shorter:
par(mfrow=1:2)
lapply(0:4, function(l) curve(weibull(0.5, 2^l, x), col=l+1, add=l!=0, ylim=c(0,50), xlim=c(0,2)))
lapply(0:4, function(l) curve(weibull(1, 2^l, x), col=l+1, add=l!=0, ylim=c(0,50), xlim=c(0,2)))
Ok if you're a big fan of nested lapply
's you can also do:
lapply(c(0.5,1), function(a) lapply(0:4, function(l) curve(weibull(a, 2^l, x), col=l+1, add=l!=0, ylim=c(0,50), xlim=c(0,2))))
A tidyverse alternative,
weibull <- function(alpha, lambda, time){
data.frame(time = time, value = alpha*lambda*(time^(alpha-1)))
}
library(ggplot2)
library(tidyverse)
params <- tidyr::crossing(lambda = c(1, 2, 4, 8, 16), alpha = c(0.5, 1))
params %>%
dplyr::mutate(purrr::pmap(., .f = weibull, time = seq(0, 2, length=100))) %>%
tidyr::unnest() %>%
ggplot(aes(time, value, colour=factor(lambda)))+
facet_wrap(~alpha,scales="free", ncol=2) + geom_line()
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
I'd do it with plyr and ggplot2,
weibull <- function(alpha, lambda, time){
data.frame(time = time, value = alpha*lambda*(time^(alpha-1)))
}
library(plyr)
library(ggplot2)
params <- expand.grid(lambda = c(1, 2, 4, 8, 16), alpha = c(0.5, 1))
all <- mdply(params, weibull, time = seq(0, 2, length=100))
ggplot(all, aes(time, value, colour=factor(lambda)))+
facet_wrap(~alpha,scales="free", ncol=2) + geom_line()