Duncan told you how to do this using density, another option is to use the logspline package for a different way to estimate densities. With this approach you can use the dlogspline and plogspline functions to compare your density estimates.
Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] (801) 408-8111 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Antje > Sent: Tuesday, February 05, 2008 1:22 AM > To: [EMAIL PROTECTED] > Subject: [R] two densities with same stepsize > > Hi there, > > I have two series of data. plotting the density function of > both gives me an idea about the difference of the data. But I > would like to quantify the difference I see. > > a <- rnorm(100) > b <- rnorm(100) > > da <- density(a) > db <- density(b) > > The problem is that da$x and db$x are different and so I have > difficulties to compare them... Is there any way to force the > density funtion to produce the values for the same x-steps? > Or is there any other statistical approach I should use for > comparing two density functions? I need to quantify how much > the data-series differ (density function is rather complex in > my case with skew and several maximas, so not easily to > describe as a mathematical function. > Sorry, I'm not that deep into statistics. Any comments / > keywords on this is welcome... > > Antje > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
