[Jprogramming] Remove part of rank-2 array

[David Vaughan]

Yes, thanks.
When I was trying to understand it I was just doing things like i./@$ A which gives 0 so I was confused.

On 13 Oct 2011, at 14:56, Raul Miller wrote:

>   A
> 2 3 4
> 3 4 5
> 4 5 6
>   $A
> 3 3
>   ;/@$ A
> ┌─┬─┐
> │3│3│
> └─┴─┘
>   ;&i./@$ A
> ┌─────┬─────┐
> │0 1 2│0 1 2│
> └─────┴─────┘
>   0 1 2 >:/ 0 1 2
> 1 0 0
> 1 1 0
> 1 1 1
>   A * 0 1 2 >:/ 0 1 2
> 2 0 0
> 3 4 0
> 4 5 6
> 
> Does this help?
> 
> -- 
> Raul
> 
> On Thu, Oct 13, 2011 at 9:48 AM, David Vaughan
> <purpleblues13 at googlemail.com> wrote:
>> How does that work? Using fndisplay, it suggests that it's equivalent to
>> 
>> (* $) A
>> 
>> On 13 Oct 2011, at 13:56, Raul Miller wrote:
>> 
>>> On Thu, Oct 13, 2011 at 8:52 AM, David Vaughan
>>> <purpleblues13 at googlemail.com> wrote:
>>>> I have an array like:
>>>> 
>>>> 2 3 4
>>>> 3 4 5
>>>> 4 5 6
>>>> 
>>>> but I want to delete the upper right corner like so:
>>>> 
>>>> 2 0 0
>>>> 3 4 0
>>>> 4 5 6
>>> 
>>>   A=:+/~1+i.3
>>>   (* >:/&i./@$) A
>>> 2 0 0
>>> 3 4 0
>>> 4 5 6
>>> 
>>> --
>>> Raul
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