[Jprogramming] amend question

[Sherlock, Ric]

> From: Sherlock, Ric
> > From: Brian Schott
> >
> > 	I get these results from amend, but ...
> >
> >    (2 1$70 90)  (2 1 $0 1;1 2) }"1 2 i. 2 3
> > 0 70  2
> > 3  4 70
> >
> > 0 90  2
> > 3  4 90
> >
> > 	I want the results below. How can I get the results
> > I desire changing only the shapes on the left of } or the
> > rank of } ? I can even use a solution that reshapes the
> > right hand argument using the shapes of the other arrays or
> > one that translates the right hand argument.
> >
> > 0 70  2
> > 3  4  5
> >
> > 0  1  2
> > 3  4 90
> 
> I don't think you can get what you want by only changing x & m.
> The major stumbling block is that the whole of m will apply to every
> application of x to y.
> I think you want to end up with something like the following:
> 
>    (70 90) (0 0 1;1 1 2)}  (2#,: i.2 3)
> 0 70  2
> 3  4  5
> 
> 0  1  2
> 3  4 90
> 
> Starting with
> x=: 70 90
> y=: i.2 3
> 
>    x [`((0 0 1;1 1 2)"_)`(#@[ # ,:@])} y
> 0 70  2
> 3  4  5
> 
> 0  1  2
> 3  4 90
> 
> Now you just need a verb that gives you the indicies...

If you have a list of the indicies that you need to replace with an item of x in the respective copies of y:
m=: 0 1 ,: 1 2
Then:
   x [`(m ;/@:,.~ i.@#@[)`(#@[ # ,:@])} y
0 70  2
3  4  5

0  1  2
3  4 90

Of course you can do instead:
   midx=: ;/ (i.#x) ,. m
   y2=: (#x) # ,: y
   x midx} y2
0 70  2
3  4  5

0  1  2
3  4 90