[R] R: chi-Squared distribution in Friedman test

[Vito Ricci]

Hi,

pchisq -> distribution function
dchisq -> density function

pval is the area under the curve, to calculte it you
use distribution function which is the integral of
density function. See:

http://www.itl.nist.gov/div898/handbook/eda/section3/eda362.htm
http://mathworld.wolfram.com/DistributionFunction.html


f(x) density function
F(x) distribution function =Pr(X<x)= integral(f(x))

Hoping I helped you!
Regards
Vito

you wrote:

Dear R helpers:

Thanks for the previous reply. I am using Friedman
racing test. According the the book "Pratical
Nonprametric Statistic" by WJ Conover, after computing
the statistics, he suggested to use chi-squared or F
distribution to accept or reject null hypothesis.
After looking into the source code, I found that R
uses chi-sqaured distribution as below:

PVAL <- pchisq(STATISTIC, PARAMETER, lower = FALSE)

but still I cant figure out why they are using this
pschisq insted of dchisq. Sorry I am wrong!!


Thanking you
truly
Prasanna











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