Krishna wrote: > Hi Mr. Cleland > > it worked excellently well, and i believe the same logic or function > by() can be used even for running regressions on subsets of huge > datasets. correct me if iam wrong
Yes. For example, the FUN argument to by() can be a summary of a linear model: by(warpbreaks, warpbreaks$tension, function(x) summary(lm(breaks ~ wool, data=x))) > thank you for the help > > rgds > > snvk > > On 8/24/05, Krishna <[EMAIL PROTECTED]> wrote: > >>Hi Mr. Cleland >> >>Could you please detail the function. >> >>Thanks and best regards >> >>snvk >> >>On 8/24/05, Chuck Cleland <[EMAIL PROTECTED]> wrote: >> >>>by(mydata, mydata$GROUPING, function(x) cor(x$x, x$y, use="pair")) >>> >>>?by >>> >>>Krishna wrote: >>> >>>>Hi all >>>> >>>>Having searched the available documentation on R, I request for help >>>>in sorting out the underlying problem. >>>> >>>>I have a huge dataset containing 2 variables x and y, which is a daily >>>>price series. >>>> >>>>I would like to observe the quarterly correlations among these two >>>>variables. Is there anyway where i can calculate cor.coeff by using a >>>>grouping variable in R. >>>> >>>>thanks in advance for the help >>>> >>>>rgds >>>> >>>>snvk >>>> >>>>______________________________________________ >>>>R-help@stat.math.ethz.ch mailing list >>>>https://stat.ethz.ch/mailman/listinfo/r-help >>>>PLEASE do read the posting guide! >>>>http://www.R-project.org/posting-guide.html >>>> >>> >>>-- >>>Chuck Cleland, Ph.D. >>>NDRI, Inc. >>>71 West 23rd Street, 8th floor >>>New York, NY 10010 >>>tel: (212) 845-4495 (Tu, Th) >>>tel: (732) 452-1424 (M, W, F) >>>fax: (917) 438-0894 >>> >> > > -- Chuck Cleland, Ph.D. NDRI, Inc. 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 452-1424 (M, W, F) fax: (917) 438-0894 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html