Hi, all. This is a real newbie question involving amend }. I have an
arbitrary matrix MAT = 2 3 4 $ i.100.
mat
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15
16 17 18 19
20 21 22 23
I want to substitute the first row of each plane with new lists. I extract
the original lists and multiple them by 100 by 0{"2 mat
100* 0{"2 mat
0 100 200 300
1200 1300 1400 1500
Now comes the surprise. I can't reverse the process of amending the original
matrix with amend }
(100* 0{"2 mat) 0}"2 mat
|rank error
| (100*0{"2 mat) 0}"2 mat
I can do this with explicit indexing
(100* 0{"2 mat) (<0 1; 0; 0 1 2 3) } mat
0 100 200 300
4 5 6 7
8 9 10 11
1200 1300 1400 1500
16 17 18 19
20 21 22 23
But when I tried using a: to index all planes and columns, I get a length
error
(100* 0{"2 mat) (<a:; 0; a:) } mat
|length error
I tried parentheses and the like but still got the error. I suspect this one
is simple syntax but the first one puzzles me.
Any wisdom on this would be much appreciated.
Bob
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