From: David Winsemius <dwinsemius_at_comcast.net>

Date: Thu, 24 Jan 2008 15:24:11 +0000 (UTC)

Date: Thu, 24 Jan 2008 15:24:11 +0000 (UTC)

Rainer M Krug <r.m.krug_at_gmail.com> wrote in news:4798991D.3000607_at_gmail.com:

*> Hi
**>
*

> I have some density estimates obtained from density(). I would like

*> to calculate the sum of squares of these. As the x values of the
**> estimates are not the same, and I would prefer not to restrict the
**> estiomate to a certain range of x values, how can I do the
**> calculation?
**>
**> Lets say:
**>
**> d1 <- density(Data1)
**> d2 <- density(Data2)
**>
**> If the x values would be the same, I would:
**>
**> ssq <- sum( (d1$y - d2$y)^2 )
**>
**> but as it isn't, I can't do that.
**>
**> is there an easy way to get the sum of squares?
*

Presumably there is a common domain for these densities. Consider forcing the x values to be the same by identically specifying n=, from=, and to=?

*> ?density
**> x <- rnorm(200,1,1)
**> x2 <- rnorm(200,1,1)
**> d1 <- density(x, n=512, from=-1, to= 4)
**> d2 <- density(x2, n=512, from=-1, to= 4)
*

> ssq <- sum( (d1$y - d2$y)^2 )

*> ssq
*

[1] 0.4722924

*> x <- rnorm(200,1,1)
**> x2 <- rnorm(200,1.5,1)
**> d1 <- density(x, n=512, from=-1, to= 4)
**> d2 <- density(x2, n=512, from=-1, to= 4)
*

> ssq <- sum( (d1$y - d2$y)^2 )

*> ssq
*

[1] 2.111498

-- David Winsemius ______________________________________________ R-help_at_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.Received on Thu 24 Jan 2008 - 15:33:04 GMT

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