even shorter:
diag4=: *=@\:
diag4 9 7 5 3
9 0 0 0
0 7 0 0
0 0 5 0
0 0 0 3
Patrick
On Wed, 26 Feb 2014, km wrote:
(*"0 1 =@i.@#) 1 2 3
1 0 0
0 2 0
0 0 3
--Kip Murray
Sent from my iPad
On Feb 26, 2014, at 9:35 PM, Roger Hui <[email protected]> wrote:
diag=: 3 : 'y (,&.>~i.#y)} 0 $~ ,~#y'
diag 10 20 30 40
10 0 0 0
0 20 0 0
0 0 30 0
0 0 0 40
diag1=: ]\ * =/~@i.@#
diag1 10 20 30 40
10 0 0 0
0 20 0 0
0 0 30 0
0 0 0 40
diag2=: -@>:@i.@# {."0 ]
diag2 10 20 30 40
10 0 0 0
0 20 0 0
0 0 30 0
0 0 0 40
diag3=: ,~@# $ ] #~ 1 j. #
diag3 10 20 30 40
10 0 0 0
0 20 0 0
0 0 30 0
0 0 0 40
On Wed, Feb 26, 2014 at 7:12 PM, Joe Bogner <[email protected]> wrote:
Sorry, I figured it out:
I just needed one more 0...
] S * (4 4 $ 1 0 0 0 0)
4 0 0 0
0 3 0 0
0 0 2.23607 0
0 0 0 0
On Wed, Feb 26, 2014 at 10:02 PM, Joe Bogner <[email protected]> wrote:
I'm experimenting with svd and am looking for a nicer way of creating
a matrix from the S diagonal
4 3 2.23607 0
needs to be
] (4 4 $ 4 0 0 0 0 3 0 0 0 0 2.23607 0 0 0 0 0 )
4 0 0 0
0 3 0 0
0 0 2.23607 0
0 0 0 0
What would be the idiomatic way to make that conversion? I tried
various versions of reshape and insert.
Not quite...
],\ S
4 0 0 0
4 3 0 0
4 3 2.23607 0
4 3 2.23607 0
I also thought about multiplying it by a diagonal matrix of 0s and 1s
but couldn't get that figured out either
Thanks
Joe
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
