[R] graphing the normal distribution

[Peter Dalgaard BSA]

David White <dwhite at ling.ohio-state.edu> writes:

> Hello,
> 
> I'd like to make some simple example graphs of the normal distribution,
> varying standard deviation, mean, and kurtosis across examples.
> 
> I have been able to manipulate mean and sd using rnorm and hist:
> y_hist(rnorm(1000000, mean=100, sd=50), 50, plot=F)
> plot(y$mid,y$count,type="l")
> 
> Two questions:
> 
> 1) n=100000 seems like a lot of samples to approach a smooth
> curve. Is there a way to make the curve smooth, but computationally less
> demanding?

Perhaps

curve(dnorm(x,mean=0,sd=1),from=-3,to=3) 

etc.?


> 2) What can I do to change the "peakiness" of the distribution?

Nothing within the Normal distribution family since it has constant
shape... the t-distributions have bigger kurtosis for given variance
as far as I recall, and uniform distributions have less. (Don't shoot
me if I got that wrong, it's not like I need to use it every day.)

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
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