]B=:2 4 $3 5 5 4 2 1 1 6
3 5 5 4
2 1 1 6
rad=: 13 :'(A=:1,-. 2-:/\|:y)#"1 y'
ifany=: ^:(*@#@])
ifany B
|syntax error
| ifany B
rad ifany B
3 5 4
2 1 6
I've never noticed a function that doesn't work, used in a sentence to
produce a good result!
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Linda Alvord
Sent: Thursday, October 04, 2012 8:12 PM
To: [email protected]
Subject: Re: [Jprogramming] Why the length error?
I think I only need "ifany" . But I could call it "ifempty" .
ifany=: ^:(*@#@])
rad=: 13 :'(1,-. 2-:/\|:y)#"1 y'
]B=:2 4 $3 5 5 4 2 1 1 6
3 5 5 4
2 1 1 6
rad ifany B
3 5 4
2 1 6
rad ifany C=:''
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Henry Rich
Sent: Thursday, October 04, 2012 7:38 PM
To: [email protected]
Subject: Re: [Jprogramming] Why the length error?
I use
ifany=: ^:(*@#@])
butifnull =: 2 : 'v"_`u@.(*@#@])'
rad ifany C
rad butifnull (2 0$0) C
Henry Rich
On 10/4/2012 7:22 PM, Linda Alvord wrote:
> I just realized that all these choices, change B in some way. I want
> it to always be a two row table of pairs in columns.
>
> B=:2 4 $3 5 5 4 2 1 1 6
> 3 5 5 4
> 2 1 1 6
>
> ''$ B
> 3 5 5 4
> {. B
> 3 5 5 4
> 0 { B
> 3 5 5 4
> ,/ B
> 3 5 5 4 2 1 1 6
>
> My only concern is when B happens to have no pairs, in which case I
> want a result that is an empty array when rad is used.
>
> I'm glad I noticed these problems as they would have caused even more
grief.
>
> Thanks for you continuing assistance.
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Raul
> Miller
> Sent: Thursday, October 04, 2012 11:34 AM
> To: [email protected]
> Subject: Re: [Jprogramming] Why the length error?
>
> Here are some options (I'm repeating concepts expressed by Roger Hui
> and Devon McCormick:
>
> L=: 1,''
> ''$ L
> {. L
> 0 { L
> ,/ L
>
> Roger's suggestion is equivalent to the APL classic in this context,
> but in the general case you would need to ravel the right argument if
> L had a rank greater than 1 (APL's rho is like ($,) in J).
>
> {. L and ''$L and 0 { L do exactly the same thing, but the syntax is
> different, which can be significant if you are building a train
> (Roger's approach re-expresses nicely as a fork -- 0 { L is also nice
> in a fork but since numbers stick to other numbers to form numeric
> words it's not quite as nice as Roger's approach)..
>
> ,/ L is different -- the others will discard extra elements and always
> reduce the rank of the result while ,/ removes a leading dimension but
> never gets rid of any elements (so if you have multiple elements it
> will not take you below rank 1).
>
> Anyways... simplest depends on you and where you are going. And note
> that there's other options also, depending... (+/L for example, would
> also get you an atomic 1 in this case)..
>
> --
> Raul
>
> On Thu, Oct 4, 2012 at 9:35 AM, Linda Alvord <[email protected]>
> wrote:
>> This is the crux of the problem:
>>
>> 1,''
>> 1
>> $1
>> $1,''
>> 1
>>
>> What is the simplest way to make the shape of 1,'' be empty?
>>
>> Linda
>>
>>
>> -----Original Messapege-----
>> From: [email protected]
>> [mailto:[email protected]] On Behalf Of Ric
>> Sherlock
>> Sent: Thursday, October 04, 2012 2:40 AM
>> To: [email protected]
>> Subject: Re: [Jprogramming] Why the length error?
>>
>> This gives a length error because
>> (1,'') # ''
>> |length error
>> | (1,'') #''
>>
>> An simple solution to your problem is to returns the input on error:
>> rad=: (#~ [: -. 0 , 2 -:/\ ])@|: :: ]
>> rad ''
>>
>> rad B
>> 3 2
>> 5 1
>> 4 6
>>
>> On Thu, Oct 4, 2012 at 6:41 PM, Linda Alvord
>> <[email protected]>
>> wrote:
>>>
>>> rad=: 13 :'(A=:1,-. 2-:/\|:y)#"1 y' NB. Remove adjacent
>>> duplicates
>>>
>>> ]B=:2 4 $3 5 5 4 2 1 1 6
>>> 3 5 5 4
>>> 2 1 1 6
>>> rad B
>>> 3 5 4
>>> 2 1 6
>>>
>>>
>>> The verb rad works as expected, but suppose in an earlier step B
>>> has become empty, I get a length error. Why does this happen?
>>>
>>>
>>> C=:''
>>> rad C
>>> |length error: rad
>>> | (A=:1,-.2-:/\|:y) #"1 y
>>> A
>>> 1
>>> 1#"1 C
>>>
>>> What can I do to get an empty result?
>>>
>>> Linda
>>>
>>> --------------------------------------------------------------------
>>> -
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>>> http://www.jsoftware.com/forums.htm
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>>
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