Dear Giampiero, > storage.mode(1) [1] "double" > storage.mode(1:1) [1] "integer"
as.integer(1) would perhaps be the more pedagogical way to program this. Best wishes Wolfgang ------------------------------------------------------------------ Wolfgang Huber EBI/EMBL Cambridge UK http://www.ebi.ac.uk/huber > Hi, > I was checking the source code to the function combn that "generates > all combinations of the elements of 'x' taken 'm' at a time.", > because I wished to modify it. I have a doubt about a statement. > This is the main loop. > > ._1 <- 1:1 > nmmp1 <- n - m + ._1 > while (a[1] != nmmp1) { > if (e < n - h) { > h <- ._1 > e <- a[m] > j <- ._1 > } > else { > e <- a[m - h] > h <- h + ._1 > j <- 1:h > } > a[m - h + j] <- e + j > r <- if (nofun) > x[a] > else FUN(x[a], ...) > if (simplify) > out[, i] <- r > else out[[i]] <- r > i <- i + 1 > } > > I wonder what is the meaning of the statement "._1 <- 1:1". > First question: what is the difference with "._1 <- 1"? > Second question (perhaps answerd by the answer to the first): why not > using "1" directly? E.g.: > [...] > h <- 1 > e <- a[m] > e <- 1 > [...] > > Sorry if this is covered by the manuals, but it's not easy to search > for the string "._1" with the usual search engines. > Thank you! > Giampiero ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
