Hello,

Try

curve(dexp(x, rate=lambda), add=TRUE)

Hope this helps,

Rui Barradas

Em 07-05-2013 14:18, Manta escreveu:

> Dear all,

>

> I have a large vector of durations (in seconds) and I create an histogram as

> follows:

>

> hist(durations,breaks=500,xlim=c(0,2000),main="",xlab="Duration

> (Seconds)",ylab="Frequency (%)",prob=TRUE)

>

> Next, I would like to superimpose the exponential distribution with the

> maximum likelihood estimate of lambda. To do so, I first calculate get the

> estimate of lambda and then try to add the curve in the following way (with

> error):

>

> library(MASS)

> lambda=fitdistr(durations,"exponential")$estimate

> curve(rexp(10000,rate=lambda),add=TRUE)

>

> Error in curve(rexp(10000,rate=lambda),add=TRUE) : 'expr' must be a

> function, or a call or an expression containing 'x'.

>

> So I need to have an 'x', OK. But doing this does not work either:

> curve(dexp(durations,rate=lambda),add=TRUE)

>

> What am I doing wrong?

>

>

>

>

>

> --

> View this message in context:

http://r.789695.n4.nabble.com/Superimpose-exponential-density-function-to-histogram-tp4666468.html> Sent from the R help mailing list archive at Nabble.com.

>

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https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide

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