On Sun, Aug 14, 2011 at 8:41 PM, Chintanu <chint...@gmail.com> wrote:
> Hello Joshua,
>
> I could feel that my explanation was bad so far. Now, giving another effort
> here to simplify things :
>
> I have a dataframe ("file") containing 8 samples (in columns). Those
> samples' results (numericals) are available in the dataframe's rows.
>
> LGD is another vector.
>
> LGD <- c(11.6, 12.3, 15.8, 33.1, 43.5, 51.3, 67.3, 84.9)
>
> Now, correlation needs to be found between -
>
> i) each of the rows of the dataframe, and
> ii) LGDAh, rows, then try: apply(file[1:47321, 3:10], 1, cor, y = LGD) it is basically an implicit for loop that loops through the first argument (your file matrix), row by row, correlating each row with LGD. So: cor(file[1, 3:10], LGD) from 1 to 47321. It is not very efficient, but even on my slow laptop it is a matter of seconds so speed is probably not a big issue unless it is part of a simulation or something. I have a sense that a smidge of clever work with matrices could avoid the apply() call, but its not jumping out at me. Cheers! Josh > Thanks, > Chintanu > > > > =============================================================== > > On Mon, Aug 15, 2011 at 1:12 PM, Joshua Wiley <jwiley.ps...@gmail.com> > wrote: >> >> On Sun, Aug 14, 2011 at 7:21 PM, Chintanu <chint...@gmail.com> wrote: >> > Hi Joshua, >> > >> > SORRY for not making that clear. I wish to have the correlation values >> > between each column of my "file" with the "LGD". For example: >> > >> > cor (Column 1, LGD) >> > cor (column 2, LGD) ... so on. >> >> Okay, you need to make a tractable example. Create or give us data >> where cor(Column1, LGD) works. LGD is a vector of length 8, file is >> probably some sort of matrix or data frame, which you are extracting >> part of, but there are way too many possible ways to repeat, >> transpose, twist, and otherwise manipulate the data into some sort of >> correlatable form (using rep() is not sufficient---that just gives you >> a really long vector). >> >> If you are currently under the impression that it is possible to >> correlate a 47231 x 1 matrix with a vector of length 8, read the >> Wikipedia page so you understand how correlation works: >> http://en.wikipedia.org/wiki/Correlation_and_dependence. >> >> > >> > The first one you have provided is producing an error : >> > >> >> sapply(file[1:47231, 3:10], FUN = cor, y = rep(LGD, 47231), method = >> >> "pearson") >> > Error in FUN(X[[1L]], ...) : incompatible dimensions >> > Cheers, >> > Chintanu >> > >> > >> > =============================================== >> > >> > On Mon, Aug 15, 2011 at 12:09 PM, Joshua Wiley <jwiley.ps...@gmail.com> >> > wrote: >> >> >> >> Hi Chintanu, >> >> >> >> Do you want the correlation of columns 3:10 of file with the y vector >> >> or do you want a correlation matrix of all variables? >> >> >> >> ## correlation between cols 3:10 and y >> >> sapply(file[1:47231, 3:10], FUN = cor, y = rep(LGD, 47231), method = >> >> "pearson") >> >> >> >> ## correlation matrix >> >> cor(cbind(file[1:47231, 3:10], rep(LGD, 47231)), method = "pearson") >> >> >> >> HTH, >> >> >> >> Josh >> >> >> >> >> >> On Sun, Aug 14, 2011 at 7:02 PM, Chintanu <chint...@gmail.com> wrote: >> >> > Hi, >> >> > >> >> > I am not sure how to fix the following error. >> >> > >> >> > LGD <- c(11.6, 12.3, 15.8, 33.1, 43.5, 51.3, >> >> > 67.3, 84.9) >> >> > >> >> > cor (x=(file [1:47231,3:10]), y= rep (LGD, 47231), method = >> >> > "pearson") >> >> > >> >> > Error in cor(x = (file[1:47231, 3:10]), y = rep(LGD, 47231), method = >> >> > "pearson") : >> >> > >> >> > incompatible dimensions >> >> > >> >> >> sessionInfo() >> >> > >> >> > R version 2.13.0 (2011-04-13) >> >> > >> >> > Platform: i386-pc-mingw32/i386 (32-bit) >> >> > >> >> > locale: >> >> > >> >> > [1] LC_COLLATE=English_Australia.1252 >> >> > LC_CTYPE=English_Australia.1252 >> >> > LC_MONETARY=English_Australia.1252 >> >> > LC_NUMERIC=C LC_TIME=English_Australia.1252 >> >> > >> >> > attached base packages: >> >> > >> >> > [1] stats graphics grDevices utils datasets methods base >> >> > >> >> > loaded via a namespace (and not attached): >> >> > >> >> > [1] tools_2.13.0 >> >> > >> >> > Thank you. >> >> > >> >> > Kind regards, >> >> > >> >> > Chintanu >> >> > >> >> > [[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. >> >> > >> >> >> >> >> >> >> >> -- >> >> Joshua Wiley >> >> Ph.D. Student, Health Psychology >> >> Programmer Analyst II, ATS Statistical Consulting Group >> >> University of California, Los Angeles >> >> https://joshuawiley.com/ >> > >> > >> >> >> >> -- >> Joshua Wiley >> Ph.D. Student, Health Psychology >> Programmer Analyst II, ATS Statistical Consulting Group >> University of California, Los Angeles >> https://joshuawiley.com/ > > -- Joshua Wiley Ph.D. Student, Health Psychology Programmer Analyst II, ATS Statistical Consulting Group University of California, Los Angeles https://joshuawiley.com/ ______________________________________________ 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.
