[Jprogramming] Index of item in table

[Gilles Kirouac]

With p defined as
  p=.3 4 5$?.60$50  NB. ?.

  33 (($@])#:[(I.@:=),@]) p
0 2 0
2 1 1
2 3 1

~ Gilles

Le 2023-12-26 à 21:06, 'Skip Cave' via Programming a écrit :
> What would a general "find the index of the value x in the array y" verb
> named fixv look like?
> 
> It would work like this:
> 
> ] p=.3 4 5$?60$50
> 
> 10 49 11 0 4
> 
> 39 33 34 32 38
> 
> 49 24 43 36 41
> 
> 1 21 11 14 27
> 
> 
> 7 28 38 9 26
> 
> 24 42 39 12 3
> 
> 8 28 33 1 4
> 
> 46 40 7 49 0
> 
> 
> 10 8 49 37 39
> 
> 5 45 46 39 6
> 
> 7 38 32 2 7
> 
> 5 10 48 16 37
> 
> 
> 45 fixv p
> 
> 2 1 1
> 
> 
> If there were more than one match, what should the output be?
> 
> 
> Skip Cave
> Cave Consulting LLC
> 
> 
> On Tue, Dec 26, 2023 at 7:48 PM LdBeth <andpuke at foxmail.com> wrote:
> 
>> This is related to the question I asked several days ago,
>>
>> http://jsoftware.com/pipermail/programming/2023-December/062994.html
>>
>> My suggestion would be
>>
>>   8 (($@])#:[i.~,@]) A
>> 1 3
>>
>> Although you might want to an alternative behavior when there are
>> multiple matches.
>>
>> LdBeth :)
>>
>>>>>>> In <CAMw+KcroqQ4g=
>> O4rKysTUQVjqQQTfxpqjy38ZwArNCD_TTLzgA at mail.gmail.com>
>>>>>>>    David Pinchbeck <dpinchbe at gmail.com> wrote:
>>> Having trouble finding this in the wiki:  I know that we can select from
>> a
>>> table using a boxed pair
>>
>>> A
>>
>>> 0 1 2 3 4
>>
>>> 5 6 7 8 9
>>
>>> 10 11 12 13 14
>>
>>> 15 16 17 18 19
>>
>>> 20 21 22 23 24
>>
>>
>>> (<1 3){A
>>
>>> 8
>>
>>> How do I write a verb f to do the reverse, so that
>>> 8 f A
>>> yields the result 1 3  ?
>>
>>> Thanks,
>>> David
>>> --
>>> David Pinchbeck
>>> Associate Professor of Mathematics
>>> St. Joseph's College
>>> Standish, ME
>>> ----------------------------------------------------------------------
>>> 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