Very true, the resounding echo was large. Thanks, Doug.
> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf > Of Douglas Bates > Sent: Wednesday, July 19, 2006 4:20 PM > To: Doran, Harold > Cc: r-help@stat.math.ethz.ch > Subject: Re: [R] Wrap a loop inside a function > > I'm sure when you read this there will be the sound of a palm > slapping a forehead. :-) > > The value of a function is the value of the last expression > evaluated in the function. If you rewrite foo as > > foo <- function(theta,items, score){ > like.mat <- matrix(numeric(length(items) * length(theta)), > ncol = length(theta)) > for(i in 1:length(items)) > like.mat[i, ] <- pcm(theta, items[[i]], score[[i]]) > like.mat > } > > you will get the result that you want. > > On 7/19/06, Doran, Harold <[EMAIL PROTECTED]> wrote: > > I need to wrap a loop inside a function and am having a > small bit of > > difficulty getting the results I need. Below is a > replicable example. > > > > > > # define functions > > pcm <- function(theta,d,score){ > > exp(rowSums(outer(theta,d[1:score],'-')))/ > > apply(exp(apply(outer(theta,d, '-'), 1, cumsum)), 2, sum) > > } > > > > foo <- function(theta,items, score){ > > like.mat <- matrix(numeric(length(items) * length(theta)), ncol = > > length(theta)) > > for(i in 1:length(items)) like.mat[i, ] <- pcm(theta, items[[i]], > > score[[i]]) > > } > > > > # begin example > > theta <- c(-1,-.5,0,.5,1) > > items <- list(item1 = c(0,1,2), item2 = c(0,1), item3 = > c(0,1,2,3,4), > > item4 = c(0,1)) > > score <- c(2,1,3,1) > > (foo(theta, items, score)) > > > > # R output from function foo > > [1] 0.8807971 0.8175745 0.7310586 0.6224593 0.5000000 > > > > > > However, what I am expecting from the function foo is > > > > > like.mat > > [,1] [,2] [,3] [,4] [,5] > > [1,] 0.118499655 0.17973411 0.25949646 0.34820743 0.4223188 [2,] > > 0.880797078 0.81757448 0.73105858 0.62245933 0.5000000 [3,] > > 0.005899109 0.01474683 0.03505661 0.07718843 0.1520072 [4,] > > 0.880797078 0.81757448 0.73105858 0.62245933 0.5000000 > > > > > > I cannot seem to track down why the function foo is only > keeping the > > last row of the full matrix I need. Can anyone see where my > error is? > > > > Thanks, > > Harold > > > > platform i386-pc-mingw32 > > arch i386 > > os mingw32 > > system i386, mingw32 > > status > > major 2 > > minor 3.0 > > year 2006 > > month 04 > > day 24 > > svn rev 37909 > > language R > > version.string Version 2.3.0 (2006-04-24) > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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 > > and provide commented, minimal, self-contained, reproducible code. > > > ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.