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Re: Normality test

• To: mathgroup at smc.vnet.net
• Subject: [mg107100] Re: Normality test
• From: Ray Koopman <koopman at sfu.ca>
• Date: Tue, 2 Feb 2010 06:54:41 -0500 (EST)
• References: <hk8nns$8jv$1@smc.vnet.net>

On Feb 2, 12:28 am, michael partensky <parten... at gmail.com> wrote:
> Hi.
> I wonder if anybody knows a function similar to qqnorm(data) from *R*,
> producing a normal scores plot, or some related tools in M. for testing
> normality of data?
>
> Thanks
> Michael Partenskii

qqnorm[y_] := Block[
 {n = Length@y, m = Mean@y, s = StandardDeviation@y, x},
 x = InverseErf[Range[1-n,n-1,2]/n]*Sqrt[2.];
 ListPlot[Transpose@{x,Sort@y},
  PlotRange->All, Frame->True, Axes->None, AspectRatio->1,
  Prolog->Line[{{x[[1]],x[[1]]*s+m},{x[[-1]],x[[-1]]*s+m}}],
  FrameLabel->{"Theoretical Standard Normal Quantiles",
               "Observed Quantiles"}]]

• Follow-Ups:
  • Re: Re: Normality test
    • From: michael partensky <partensky@gmail.com>