Hi.
The following is just an example for generalized case.
]dat=:2 3 4 $1
1 1 1 1
1 1 1 1
1 1 1 1
1 1 1 1
1 1 1 1
1 1 1 1
1 2 *"0 dat
1 1 1 1
1 1 1 1
1 1 1 1
2 2 2 2
2 2 2 2
2 2 2 2
1 2 3 4 *"1 dat
1 2 3 4
1 2 3 4
1 2 3 4
1 2 3 4
1 2 3 4
1 2 3 4
1 2 3 *"2 dat
1 1 1 1
2 2 2 2
3 3 3 3
1 1 1 1
2 2 2 2
3 3 3 3
Tohinari Kamakura
On 2007/04/30, at 2:26, NEIL JAMES HOSEY wrote:
Thank yous very much for the advice.
I was not sure how "1 worked until now.
Neil
Translating the J answers back into English
perhaps would provide some insight:
3 2 * "1 dat
multiply every row
And working forwards from your specifications:
multiply say 3 2 by every row
* "1
----- Original Message -----
From: NEIL JAMES HOSEY <[EMAIL PROTECTED]>
Date: Sunday, April 29, 2007 3:12 am
Subject: [Jprogramming] Matrix Multiplication Problem
Hi all,
Greatly appreciate the comments about boxing last week.
It solved my problem.
I have one more question ( maybe too simple) about a
certain form of matrix multiplication ( i think its
point to point?)
Anyway say I have data matrix dat
where:
dat=
0 1
1 0
0 0
1 1
how can I multiply say 3 2 by every row. Resulting in
the following matrix:
dat =
0 2
3 0
0 0
3 2
I thought that this form of multiplication was done with
+/.* but I am getting domain errors.
Apologies about the simplcity of this question but its
driving me mad!!
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