Thanks, Chuck. Seems odd though, doesn't it? There must be something with my data set. But, I don't have any clue what it might be since I can compute pearson using by() and I can subset and actually compute spearman using just cor()
> -----Original Message----- > From: Chuck Cleland [mailto:[EMAIL PROTECTED] > Sent: Wednesday, September 19, 2007 12:14 PM > To: Doran, Harold > Cc: r-help@r-project.org > Subject: Re: [R] By() with method = spearman > > Doran, Harold wrote: > > I have a data set where I want the correlations between 2 variables > > conditional on a students grade level. > > > > This code works just fine. > > > > by(tmp[,c('mtsc07', 'DCBASmathscoreSPRING')], tmp$Grade, cor, > > use='complete', method='pearson') > > > > However, this generates an error > > > > by(tmp[,c('mtsc07', 'DCBASmathscoreSPRING')], tmp$Grade, cor, > > use='complete', method='spearman') Error in FUN(data[x, ], > ...) : 'x' > > is empty > > > > I can subset the data by grade and compute spearman rho as > > > > tmp5 <- subset(tmp, Grade == 5) > > cor(tmp5[,c('mtsc07', 'DCBASmathcountSPRING')], use='complete', > > method='spearman') > > > > But doing this iteratively is inefficient. > > > > I don't see anything in the help man for by() or cor() that > tells me > > what the problem is. I might be missing it though. Any thoughts? > > It works as expected using the iris data: > > by(iris[,c('Sepal.Length', 'Sepal.Width')], iris$Species, cor, > use='complete', method='spearman') > > iris$Species: setosa > Sepal.Length Sepal.Width > Sepal.Length 1.0000000 0.7553375 > Sepal.Width 0.7553375 1.0000000 > -------------------------------------------------------------- > ------------------------------------------------------- > > iris$Species: versicolor > Sepal.Length Sepal.Width > Sepal.Length 1.000000 0.517606 > Sepal.Width 0.517606 1.000000 > -------------------------------------------------------------- > ------------------------------------------------------- > > iris$Species: virginica > Sepal.Length Sepal.Width > Sepal.Length 1.0000000 0.4265165 > Sepal.Width 0.4265165 1.0000000 > > > sessionInfo() > R version 2.5.1 Patched (2007-09-16 r42884) > i386-pc-mingw32 > > locale: > LC_COLLATE=English_United States.1252;LC_CTYPE=English_United > States.1252;LC_MONETARY=English_United > States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252 > > attached base packages: > [1] "stats" "graphics" "grDevices" "utils" "datasets" > "methods" "base" > > other attached packages: > lattice > "0.16-5" > > > Thanks, > > Harold > > > > > >> sessionInfo() > > R version 2.5.0 (2007-04-23) > > i386-pc-mingw32 > > > > locale: > > LC_COLLATE=English_United States.1252;LC_CTYPE=English_United > > States.1252;LC_MONETARY=English_United > > States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252 > > > > attached base packages: > > [1] "stats" "graphics" "grDevices" "utils" "datasets" > > "methods" "base" > > > > other attached packages: > > lattice > > "0.15-4" > > > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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. > > -- > Chuck Cleland, Ph.D. > NDRI, Inc. > 71 West 23rd Street, 8th floor > New York, NY 10010 > tel: (212) 845-4495 (Tu, Th) > tel: (732) 512-0171 (M, W, F) > fax: (917) 438-0894 > ______________________________________________ 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.
