David Winsemius
On Feb 13, 2009, at 8:11 AM, Jason Rupert wrote:
> 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 <ggrothendieck at gmail.com>
> wrote:
> From: Gabor Grothendieck <ggrothendieck at gmail.com>
> Subject: Re: [R] Website, book, paper, etc. that shows example plots
> of distributions?
> To: jasonkrupert at yahoo.com
> Cc: R-help at 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 <jasonkrupert at 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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>>
>
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
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