How to plot Histogram with frequence overlaid by distribution curve

histdata <- hist(samp,freq=TRUE,br=20)
curve(max(histdata$count)*dnorm(x,mean=mean(samp),sd=sd(samp)),add=TRUE)

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Date:   Mon, 1 Mar 2004 17:18:12 +0800 
From:   <WeiQiang.Li at seagate.com>
To:   <r-help at stat.math.ethz.ch> 
Subject:   [R] How to plot Histogram with frequence overlaid by distribution curve 

 
Hi,
I am facing the problem that I want to plot a histogram chart set
freq to true and overlay with normal or weibull or exponential distribution
curve.

The sample code is shown as below:

samp<-c(-8.2262,-8.2262,-8.2262,-8.20209,-8.09294,-8.07321,-8.07321,

-8.07321,-8.07175,-8.04948,-8.04948,-8.04948,-8.03848,-8.03848,
-8.026,-7.92517,-7.92517,-7.77218,-7.62414,-7.62414,-7.62414,
-7.59027,-7.59027,-7.59027,-7.59027,-7.59027,-7.59027,-7.28924,
-7.28924,-6.78729,-6.25307)

hist(samp,freq=TRUE,br=20)
curve(dnorm(x,mean=mean(samp),sd=sd(samp)),add=TRUE)

In the chart created based on above command, curve scale is too small
compared to the freqeunce. My question here is how to adjust the scale of
distribution curve. Thanks !

Best Regards
WeiQiang Li