Aliases: rowCollapse colCollapse
Keywords: utilities
### ** Examples x <- matrix(1:27, ncol = 3) y <- rowCollapse(x, 1) stopifnot(identical(y, x[, 1])) y <- rowCollapse(x, 2) stopifnot(identical(y, x[, 2])) y <- rowCollapse(x, c(1, 1, 1, 1, 1, 3, 3, 3, 3)) stopifnot(identical(y, c(x[1:5, 1], x[6:9, 3]))) y <- rowCollapse(x, 1:3) print(y)
[1] 1 11 21 4 14 24 7 17 27
y_truth <- c(x[1, 1], x[2, 2], x[3, 3], x[4, 1], x[5, 2], x[6, 3], x[7, 1], x[8, 2], x[9, 3]) stopifnot(identical(y, y_truth))