Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2004
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2004

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: how to graphically fill the tails of a normal distribution

  • To: mathgroup at smc.vnet.net
  • Subject: [mg50019] Re: how to graphically fill the tails of a normal distribution
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Thu, 12 Aug 2004 05:43:24 -0400 (EDT)
  • Organization: Universitaet Leipzig
  • References: <cfcr0h$46q$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

Needs["Statistics`NormalDistribution`"]
Needs["Graphics`FilledPlot`"]

ndist = NormalDistribution[0, 1];

npdf = PDF[ndist, x]

FilledPlot[{npdf, If[Abs[x] > 2, 0, npdf]}, {x, -4, 4}, 
  Fills -> RGBColor[1, 0, 0], PlotRange -> All];

??

Regards
  Jens

Todd Allen wrote:
> 
> Hello all,
> 
>       Hope you don't mind a question from a biologist trying to learn Mathematica.  I have been teaching myself the syntax of Mathematica to analyze microarray data (i.e, a technology to simultaneously monitor the expression levels of thousands of genes).  I am interested in producing a plot for a presentation in which the tails of a normal distribution are colored red to illustrate a concept.  I can get the plot to work with a single tail, but I can't get the syntax to work for both tails of the disribution.  Here is my code:
> 
> This works for a single tail, with the following code (necessary packages already loaded):
> ndist=NormalDistribution[0,1]
> 
> npdf=PDF[ndist,x]
> 
> FilledPlot[{npdf,If[x³2,0,npdf]},{x,-4,4},Fills®RGBColor[1,0,0]]
> 
> However when I try the following with the Or operator (at least I think Or operator):
> 
> FilledPlot[{npdf,If[x³2.0þx£-2.0,0,npdf]},{x,-4,4},Fills®RGBColor[1,0,0]]
> 
> I get a series of error messages:
> 
> Plot:plnr:If[x³2.0þx£-2.0,0,npdf] is not a machine-size real number at x=-4
> 
> This error repeats itself with different x values and then a normal curve is drawn with neither tail colored in.
> 
> 
> What am I missing here?
> 
> Any insight is much appreciated, thanks!
> Todd


  • Prev by Date: Re: How to install Combinatorica
  • Next by Date: Re: how to graphically fill the tails of a normal distribution
  • Previous by thread: Re: how to graphically fill the tails of a normal distribution
  • Next by thread: Re: how to graphically fill the tails of a normal distribution