[R] cdf in R give probability of random variable

peter dalgaard pdalgd at gmail.com
Fri Oct 21 20:23:42 CEST 2016


This looks like homework, but doing it in R might not be, so I'll give you the benefit of doubt...


> On 21 Oct 2016, at 18:30 , Ragia . <ragia11 at hotmail.com> wrote:
> 
> 
> Dear Grooup
> 
> kindly
> 
> how can I plot  these  graphs in R..
> 
> 
> Suppose that X is a discrete random variable with P(X = 0) = .25, P(X = 1) =
> .125, P(X = 2) = .125, and P(X = 3) = .5. Graph the frequency function and
> the cumulative distribution function of X.
> 
> 
> 
> my solution was:
> 
> x=c(0,1,3)
> px=c(.25,.125,.5)
> plot( x,px ,type="h"  ) # to plot the frequency  , is it correct
> 

You forgot X=2 in there (check the sum). 

> how to plot the cdf?
> 

cumsum() is your friend.

In both cases it works out nicer if you do

names(px) <- x
barplot(px)

-pd

> 	[[alternative HTML version deleted]]

Notice that plain text posting is strongly preferred in here. HTML messes up code badly sometimes.

-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
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Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com



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