In reply to Arne Cordes.

In your example, s[1] contains 5 words but s[2] contains only 4 words. Matrices have to be rectangular, but you are trying to create a matrix whose first row has five columns and whose second row has four columns.

You can use a loop to process each element of s:

do i = 1 to nrow(n);
words = scan(s[i], 1:n[i], delims);
print i words;
end;