Thank you very much. Thank you again regarding the suggestion below. I will
give that a shot and I guess I've got my work counted out for me. I counted 45
different distributions.
Is the best way to get a QQPlot of each, to run through producing a data set
for each distribution and then using the qqplot function to get a QQplot of the
distribution and then compare it with my data distribution?
As you can tell I am not a trained statistician, so any guidance or suggested
further reading is greatly appreciated.
I guess I am pretty sure my data is not a normal distribution due to doing some
of the empirical "Goodness of Fit" tests and comparing the QQplot of my data
against the QQPlot of a normal distribution with the same number of points. I
guess the next step is to figure out which distribution my data most closely
matches.
Also, I guess I could also fool around and take the log, sqrt, etc. of my data
and see if it will then more closely resemble a normal distribution.
Thank you again for assisting this novice data analyst who is trying to gain a
better understanding of the techniques using this powerful software package.
--- On Fri, 2/13/09, Gabor Grothendieck <ggrothendi...@gmail.com> wrote:
From: Gabor Grothendieck <ggrothendi...@gmail.com>
Subject: Re: [R] Website, book, paper, etc. that shows example plots of
distributions?
To: jasonkrup...@yahoo.com
Cc: R-help@r-project.org
Date: Friday, February 13, 2009, 5:43 AM
You can readily create a dynamic display for using qqplot and similar functions
in conjunction with either the playwith or TeachingDemos packages.
For example, to investigate the effect of the shape parameter in the skew
normal distribution on its qqplot relative to the normal distribution:
library(playwith)
library(sn)
playwith(qqnorm(rsn(100, shape = shape)),
parameters = list(shape = seq(-3, 3, .1)))
Now move the slider located at the bottom of the window that
appears and watch the plot change in response to changing
the shape value.
You can find more distributions here:
http://cran.r-project.org/web/views/Distributions.html
On Thu, Feb 12, 2009 at 1:04 PM, Jason Rupert <jasonkrup...@yahoo.com>
wrote:
> By any chance is any one aware of a website, book, paper, etc. or
combinations of those sources that show plots of different distributions?
>
> After reading a pretty good whitepaper I became aware of the benefit of I
the benefit of doing Q-Q plots and histograms to help assess a distribution.
The whitepaper is called:
> "Univariate Analysis and Normality Test Using SAS, Stata, and
SPSS*" , (c) 2002-2008 The Trustees of Indiana University Univariate
Analysis and Normality Test: 1, Hun Myoung Park
>
> Unfortunately the white paper does not provide an extensive amount of
example distributions plotted using Q-Q plots and histograms, so I am curious if
there is a "portfolio"-type website or other whitepaper shows
examples of various types of distributions.
>
> It would be helpful to see a bunch of Q-Q plots and their associated
histograms to get an idea of how the distribution looks in comparison against
the Gaussian.
>
> I think seeing the plot really helps.
>
> Thank you for any insights.
>
>
>
> [[alternative HTML version deleted]]
>
>
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>
>
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