[R] Plot qnorm

[G. Jay Kerns]

Dear Talina,

On Thu, Sep 11, 2008 at 2:28 PM, Talina Ruiz <badelfi at gmail.com> wrote:
> Hi,
>
> I have this problem:
>
> X is hazardous variable N(mean 2, sd=3)
>
>>>question 1) Find the c value, so that P(X>c)=0.10. using R
>
>>>question 2) Graph the function N(2,3) and with this graph, explain what
> you do in question number 1.
>
> I just found question number one but not the second one. So, I'd like to
> make a plot form this distribution N (2,3) using the functions plot and
> qnorm.
> I couldn't find how make it in R. Thanks for any hint.


The notation that you have used is somewhat ambiguous, in that N(2,3)
typically denotes the normal CDF (or sometimes the PDF), neither of
which being the quantile function qnorm().

But as to your specific question, the IPSUR plugin for the R Commander
will plot quantile functions.

After installing Rcdmr and RcmdrPlugin.IPSUR  (version >= 0.1-5), do

library(RcmdrPlugin.IPSUR)

and after the Commander restarts take a look at the "Distributions"
menu.  You can plot any of the above. In addition, you will have code
echoed to you for the console that you can use for other problems.

Best wishes,
Jay




***************************************************
G. Jay Kerns, Ph.D.
Associate Professor
Department of Mathematics & Statistics
Youngstown State University
Youngstown, OH 44555-0002 USA
Office: 1035 Cushwa Hall
Phone: (330) 941-3310 Office (voice mail)
-3302 Department
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E-mail: gkerns at ysu.edu
http://www.cc.ysu.edu/~gjkerns/