R table by matrix row

One alternative is to convert your matrix to a long data.frame (using stack), at which point you can easily use table:

Here's your data:

mymat <- structure(c(5L, 5L, 8L, 2L, 7L, 5L, 5L, 7L, 6L, 7L, 4L, 5L, 6L,             6L, 5L, 6L, 5L, 6L, 6L, 4L), .Dim = c(5L, 4L), .Dimnames = list(              c("a", "b", "c", "d", "e"), c("1", "2", "3", "4")))

This is what it looks like as a long data.frame:

head(stack(data.frame(t(mymat))))#   values ind# 1      5   a# 2      5   a# 3      4   a# 4      6   a# 5      5   b# 6      5   b

Here's how we can use that to create the table you want:

with(stack(data.frame(t(mymat))), table(ind, values))#    values# ind 2 4 5 6 7 8#   a 0 1 2 1 0 0#   b 0 0 4 0 0 0#   c 0 0 0 2 1 1#   d 1 0 0 3 0 0#   e 0 1 1 0 2 0

## source datax=as.matrix(read.table(text="   1  2  3  4 a  5  5  4  6    b  5  5  5  5     c  8  7  6  6   d  2  6  6  6     e  7  7  5  4"))# resulttable(rep(rownames(x),ncol(x)),c(x))#   2 4 5 6 7 8# a 0 1 2 1 0 0# b 0 0 4 0 0 0# c 0 0 0 2 1 1# d 1 0 0 3 0 0# e 0 1 1 0 2 0

I used apply too:

t(apply(mat, 1, function(x) table(factor(x, levels = unique(sort(c(mat)))))))R > mat  = matrix(sample(1:8, 20, replace = T), 5, 4)R > mat     [,1] [,2] [,3] [,4][1,]    5    6    1    4[2,]    4    3    4    8[3,]    4    8    4    3[4,]    3    3    5    1[5,]    1    1    3    1R > t(apply(mat, 1, function(x) table(factor(x, levels = unique(sort(c(mat)))))))     1 3 4 5 6 8[1,] 1 0 1 1 1 0[2,] 0 1 2 0 0 1[3,] 0 1 2 0 0 1[4,] 1 2 0 1 0 0[5,] 3 1 0 0 0 0