how to graphically fill the tails of a normal distribution
- To: mathgroup at smc.vnet.net
- Subject: [mg50012] how to graphically fill the tails of a normal distribution
- From: Todd Allen <genesplicer28 at yahoo.com>
- Date: Wed, 11 Aug 2004 05:53:11 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
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
- Follow-Ups:
- Re: how to graphically fill the tails of a normaldistribution
- From: Tomas Garza <tgarza01@prodigy.net.mx>
- Re: how to graphically fill the tails of a normal distribution
- From: DrBob <drbob@bigfoot.com>
- Re: how to graphically fill the tails of a normaldistribution