在r中绘制累积分布函数

Question

I have the following pdf,

f(x)=2(1-x)^2;  2=>x>1

Now i have to plot the cdf of the random variable in r .

#cumulative distribution function

Fx <- function(x){
          (2/3) * (x^3-3*x^2+3*x-1)
      }

R <- runif(100,1,2)

cum_prob <- Fx(R) # determining cumulative probability

But i don't know which command should i use to draw the cdf .

hist() & barplot() are not appropriate for cdf. Because as far i know plotting a cdf, it requires the values of random variable in X-axis, and cumulative probability in Y-axis.

Also my variable is continuous.

Answer 1

Responding to the code in the comment:

fx <- function(x)2*(x-1)^2 
integrate(fx,1,2)
#------------
0.6666667 with absolute error < 7.4e-15
plot(seq(1,2,by=0.01), cumsum(fx(seq(1,2,by=0.01))*0.01 ), type="l" ) 

Answer 2

You can use this:

Define density:

f <- function(x) (2*(1-x)^2)*(1<x & x<=2)

Plot density:

plot(f,0,3)

Plot CDF:

plot(Vectorize(function(X)integrate(f,0,X)$value),0,3,add=TRUE)

Note: 0 and 3 are limits of x axis in the plots; you can change them. Also note your density is not normalized.