CODEWITHSUNDEEP
r
catty
catty

Reputation: 33

How to Plot CDF and PDF in R for a new function

How can I plot CDF and PDF in R for 

 f <- function(x) {((2*a*b)/(x^3))*((exp(-b/(x^2))^a))}

with range 0 to infinity

Upvotes: 3

Views: 5101

Answers (2)

Balint Domokos
Balint Domokos

Reputation: 1021

I would use something like this (because I like ggplot2):

a <-1
b <- 2
f <- function(x) {((2*a*b)/(x^3))*((exp(-b/(x^2))^a))}

x <- seq(1, 20)
pdf <- f(x)
cdf <- cumsum(pdf)

library(ggplot2)
df <- data.frame(x, pdf, cdf)
ggplot(df, aes(x, pdf))+geom_line()
ggplot(df, aes(x, cdf))+geom_line()

Upvotes: 1

vpipkt
vpipkt

Reputation: 1707

You should specify a and b as arguments to the function, with default values. Then curve can be used to plot the function. 

f <- function(x,a=0.5,b=4.5) {((2*a*b)/(x^3))*((exp(-b/(x^2))^a))}        
curve(f)

The way your code is now, a and b are most likely resolving to whatever is in the global environment, which you may not want later and could cause problems reproducing your results.

Upvotes: 1

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