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
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