Full_Name: Steven McKinney Version: 2.9.0 OS: Mac OS X 10.5.6 Submission from: (NULL) (142.103.207.10)
A corrupt data frame can be constructed as follows: foo <- matrix(1:12, nrow = 3) bar <- data.frame(foo) bar$NewCol <- foo[foo[, 1] == 4, 4] bar lapply(bar, length) > foo <- matrix(1:12, nrow = 3) > bar <- data.frame(foo) > bar$NewCol <- foo[foo[, 1] == 4, 4] bar X1 X2 X3 X4 NewCol 1 1 4 7 10 <NA> 2 2 5 8 11 <NA> 3 3 6 9 12 <NA> Warning message: In format.data.frame(x, digits = digits, na.encode = FALSE) : corrupt data frame: columns will be truncated or padded with NAs > lapply(bar, length) $X1 [1] 3 $X2 [1] 3 $X3 [1] 3 $X4 [1] 3 $NewCol [1] 0 The data.frame method is > getAnywhere("$<-.data.frame" ) A single object matching '$<-.data.frame' was found It was found in the following places package:base registered S3 method for $<- from namespace base namespace:base with value function (x, i, value) { cl <- oldClass(x) class(x) <- NULL nrows <- .row_names_info(x, 2L) if (!is.null(value)) { N <- NROW(value) if (N > nrows) stop(gettextf("replacement has %d rows, data has %d", N, nrows), domain = NA) if (N < nrows && N > 0L) if (nrows%%N == 0L && length(dim(value)) <= 1L) value <- rep(value, length.out = nrows) else stop(gettextf("replacement has %d rows, data has %d", N, nrows), domain = NA) if (is.atomic(value)) names(value) <- NULL } x[[i]] <- value class(x) <- cl return(x) }<environment: namespace:base> > I placed a browser() command before return(x) and did some poking around. The issue is that the example above creates an object with N < nrows but N == 0L, so either an else clause to check for this condition is needed, or, it appears to me, the N > 0L part of the conditional clause needs to be moved to the next if clause. I modified the rows if (N < nrows && N > 0L) if (nrows%%N == 0L && length(dim(value)) <= 1L) to read if (N < nrows) if (N > 0L && nrows%%N == 0L && length(dim(value)) <= 1L) as in "$<-.data.frame" <- function (x, i, value) { cl <- oldClass(x) class(x) <- NULL nrows <- .row_names_info(x, 2L) if (!is.null(value)) { N <- NROW(value) if (N > nrows) stop(gettextf("replacement has %d rows, data has %d", N, nrows), domain = NA) if (N < nrows) if (N > 0L && nrows%%N == 0L && length(dim(value)) <= 1L) value <- rep(value, length.out = nrows) else stop(gettextf("replacement has %d rows, data has %d", N, nrows), domain = NA) if (is.atomic(value)) names(value) <- NULL } x[[i]] <- value class(x) <- cl return(x) } Now it detects the problem above: > foo <- matrix(1:12, nrow = 3) > bar <- data.frame(foo) > bar$NewCol <- foo[foo[, 1] == 4, 4] Error in `$<-.data.frame`(`*tmp*`, "NewCol", value = integer(0)) : replacement has 0 rows, data has 3 It doesn't appear to stumble on weird data frames (these from the ?data.frame help page) > L3 <- LETTERS[1:3] > (d <- data.frame(cbind(x=1, y=1:10), fac=sample(L3, 10, replace=TRUE))) > (d0 <- d[, FALSE]) # NULL data frame with 10 rows > (d.0 <- d[FALSE, ]) # <0 rows> data frame (3 cols) > (d00 <- d0[FALSE,]) # NULL data frame with 0 rows > d0$NewCol <- foo[foo[, 1] == 4, 4] Error in `$<-.data.frame`(`*tmp*`, "NewCol", value = integer(0)) : replacement has 0 rows, data has 10 ### Catches this problem above alright. > d.0$NewCol <- foo[foo[, 1] == 4, 4] > d.0 [1] x y fac NewCol <0 rows> (or 0-length row.names) ### Lets the above one through alright. > d00$NewCol <- foo[foo[, 1] == 4, 4] > > d00 [1] NewCol <0 rows> (or 0-length row.names) ### Lets the above one through alright. Would the above modification work to fix this problem? > sessionInfo() R version 2.9.0 (2009-04-17) powerpc-apple-darwin8.11.1 locale: en_CA.UTF-8/en_CA.UTF-8/C/C/en_CA.UTF-8/en_CA.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] nlme_3.1-90 loaded via a namespace (and not attached): [1] grid_2.9.0 lattice_0.17-22 tools_2.9.0 Also occurs on Windows box with R 2.8.1 Steven McKinney Statistician Molecular Oncology and Breast Cancer Program British Columbia Cancer Research Centre email: smckinney +at+ bccrc +dot+ ca tel: 604-675-8000 x7561 BCCRC Molecular Oncology 675 West 10th Ave, Floor 4 Vancouver B.C. V5Z 1L3 Canada ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel