If you didn't mind boxing instead of a matrix you can capture the difference
between indexing and null indicators this way.
I.@:(5&=)each 1 2 3 4; 2 3 4 5; 5 4 3 2 ; 2 3 5 4
┌┬─┬─┬─┐
││3│0│2│
└┴─┴─┴─┘
Cheers, bob
> On Jan 13, 2019, at 10:06 AM, Jimmy Gauvin <[email protected]> wrote:
>
> Hi,
>
> does this help :
>
> 5 e."1 |:1 2 3 4,. 2 3 4 5,. 5 4 3 2 ,. 2 3 5 4
> 0 1 1 1
>
>
>
> On Sun, Jan 13, 2019 at 12:56 PM 'Skip Cave' via Programming <
> [email protected]> wrote:
>
>> I know I can find the location (index) of a specific integer in a vector of
>> integers using I.
>>
>> I.5=1 2 3 4 5 4 3 4 5 6 5 6
>>
>> 4 8 10
>>
>>
>> So I want to find the row index of a specific integer in an array of
>> integers:
>>
>> |:1 2 3 4,. 2 3 4 5,. 5 4 3 2 ,. 2 3 5 4
>>
>> 1 2 3 4
>>
>> 2 3 4 5
>>
>> 5 4 3 2
>>
>> 2 3 5 4
>>
>> 5=|:1 2 3 4,. 2 3 4 5,. 5 4 3 2 ,. 2 3 5 4
>>
>> 0 0 0 0
>>
>> 0 0 0 1
>>
>> 1 0 0 0
>>
>> 0 0 1 0
>>
>> ,I. 5=|:1 2 3 4,. 2 3 4 5,. 5 4 3 2 ,. 2 3 5 4
>>
>> 0 3 0 2
>>
>>
>> The first zero indicates that there is no 5 in the first row. The second
>> zero gives the index of the 5 in the third row. How can I tell whether the
>> zero is an index, or a null indicator?
>>
>> Skip
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