Hello,
the complex number in the case 1D can be obtained as expected
doing first $r=$r->r2C
But in 2D case I still did not have succeeded to match with
dataflow on $r in the sense of the mask
For example, If I do
$r=(zeroes(3,3)->ndcoords/2-pdl(0.5,0.5))->r2C;
$rr=($r**2)->sumover->sqrt;
($r1,$r2)=where_both($rr,$rr->abs<0.2)
I obtain the expected result in $r1 and $r2 in agreement
with the mask of the vectors lengths
But, how to pass from that the respective length in the $r1
and $r2 to the vectors in $r ? It would be some index indirection that
manage these facts?
Regards
El mar, 21 ene 2025 a las 20:35, Guillermo P. Ortiz (<gor...@exa.unne.edu.ar>)
escribió:
> Hi Ed,
> yes, just I was trying with where_both
> But I get unexpected behaviour for me in 2D case
>
> 1) first in 1D
>
> pdl> $r=zeroes(3)->ndcoords/2-pdl(0.5)
>
> pdl> p $r
>
> [
> [-0.5]
> [ 0]
> [ 0.5]
> ]
>
> pdl> ($r1,$r2)=where_both($r,$r->abs < 0.2)
>
> pdl> p $r1
> [0]
>
> pdl> p $r2
> [-0.5 0.5]
>
> now, trying to modify $r following that condition
>
> pdl> $r1.=$r1+1
>
> pdl> $r2.=$r2+3
>
> pdl> p $r
>
> [
> [2.5]
> [ 1]
> [3.5]
> ]
>
> But this seem did not work for complex number
>
> pdl> $r1.=$r1*(1+i)
>
> pdl> $r2.=$r2-(1+i)
>
>
> pdl> p $r
>
> [
> [1.5]
>
> [ 1]
> [2.5]
>
> ]
>
> And, seem did not work in 2D for real case neither
>
> pdl> $r=zeroes(3,3)->ndcoords/2-pdl(0.5,0.5)
>
> pdl> p $r
>
> [
> [
> [-0.5 -0.5]
> [ 0 -0.5]
> [ 0.5 -0.5]
> ]
> [
> [-0.5 0]
> [ 0 0]
>
> [ 0.5 0]
> ]
> [
> [-0.5 0.5]
>
> [ 0 0.5]
> [ 0.5 0.5]
>
> ]
> ]
>
> pdl> ($r1,$r2)=where_both($r,($r**2)->sumover->sqrt < 0.2)
>
> pdl> p $r1
> [0.5]
>
> pdl> p $r2
> [-0.5 -0.5 0 -0.5 -0.5 -0.5 0 0]
>
> what I doing wrong here?
>
> Regards
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> El mar., 21 de enero de 2025 19:42, Ed . <ej...@hotmail.com> escribió:
>
>> Hi Guillermo,
>>
>> That does feel to me like you'd want to *not* do something on the whole
>> ndarray, but instead do something on a $pdl->where(condition...). What
>> do you think?
>>
>> Best regards,
>> Ed
>>
>> ------------------------------
>> *From:* Guillermo P. Ortiz <gor...@exa.unne.edu.ar>
>> *Sent:* 21 January 2025 19:07
>> *To:* Ed . <ej...@hotmail.com>
>> *Cc:* pdl-devel@lists.sourceforge.net <pdl-devel@lists.sourceforge.net>;
>> perldl <pdl-gene...@lists.sourceforge.net>
>> *Subject:* Re: [Pdl-devel] conditional inline
>>
>> For instance, I am trying with $r, like below
>>
>> $r=(zeroes(2*$N+1,2*$N+1)->ndcoords-pdl($N,$N))/(2*$N+1)
>>
>> Regards
>>
>> El mar, 21 ene 2025 a las 14:39, Guillermo P. Ortiz (<
>> gor...@exa.unne.edu.ar>) escribió:
>>
>> Yes Ed, you are right.
>> I want to perform different operations on $r
>> depending on its distance to a point $r0 in 2D.
>> Then, I guess that first, and because for further
>> manipulation, I decide to center $r-=$r0 in
>> such a point.
>>
>> Then in false code,
>>
>> if ( length ($r) < $a)
>> { return f($r)}
>> else
>> { return g($r) }
>>
>> where "length" I am not sure, but it could be inner($r,$r)->sqrt.
>> Maybe no ternary expression but some subroutine will be fine also.
>>
>> Regards
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> El mar, 21 ene 2025 a las 14:16, Ed . (<ej...@hotmail.com>) escribió:
>>
>> Hi Guillermo,
>>
>> That conditional will, for the case you've given, always be false,
>> because it has values more than 0.2 away from 0.5. When you use all, you
>> are asking a question about the entire ndarray, in other words for every
>> single value in it.
>>
>> I believe that there's some real problem you're trying to solve, but I'm
>> afraid I still have absolutely no idea what it is. Please help me help you!
>>
>> Best regards,
>> Ed
>>
>> ------------------------------
>> *From:* Guillermo P. Ortiz <gor...@exa.unne.edu.ar>
>> *Sent:* 21 January 2025 01:19
>> *To:* Ed . <ej...@hotmail.com>
>> *Cc:* pdl-devel@lists.sourceforge.net <pdl-devel@lists.sourceforge.net>;
>> perldl <pdl-gene...@lists.sourceforge.net>
>> *Subject:* Re: [Pdl-devel] conditional inline
>>
>> Ok, Ed,
>> That example did not work for me.
>> The conditional results seems to be allways false. I mean, that it give
>> $x also when $x is near to 0.5 than 0.2, where I is expecting the $x**2
>> result.
>>
>> Regates
>>
>>
>>
>> El El lun, 20 ene 2025 a la(s) 20:39, Ed . <ej...@hotmail.com> escribió:
>>
>> Hi Guillermo,
>>
>> You may still be having a problem, but you have yet to tell us what it
>> is. The code you sent works fine, including as many dimensions as you like
>> (because all acts on the whole ndarray at once).
>>
>> If there's a problem in there, please share it :-)
>>
>> Best regards,
>> Ed
>>
>> ------------------------------
>> *From:* Guillermo P. Ortiz <gor...@exa.unne.edu.ar>
>> *Sent:* 20 January 2025 23:35
>> *To:* Ed . <ej...@hotmail.com>
>> *Cc:* pdl-devel@lists.sourceforge.net <pdl-devel@lists.sourceforge.net>;
>> perldl <pdl-gene...@lists.sourceforge.net>
>> *Subject:* Re: [Pdl-devel] conditional inline
>>
>> Thanks Ed,
>> Using ternary conditional expression
>> I still have some problem with múltiple disensión case.
>> See my example in message befare
>>
>>
>> El El lun, 20 ene 2025 a la(s) 19:31, Ed . <ej...@hotmail.com> escribió:
>>
>> Hi Guillermo,
>>
>> You can do that indeed, that's just Perl. If you wanted to do operations
>> on a subset of that ndarray, then you'd do e.g.
>>
>> $pdl->where(($pdl-0.5)->abs < 0.2) *= 5;
>>
>> An observation is that the above condition could be a bit shorter by
>> using the recently-added approx_artol: (which would also mean it ran
>> quicker)
>>
>> $pdl->approx_artol(0.5, 0.2)
>>
>> Best regards,
>> Ed
>>
>> ------------------------------
>> *From:* Guillermo P. Ortiz <gor...@exa.unne.edu.ar>
>> *Sent:* 20 January 2025 19:39
>> *To:* pdl-devel@lists.sourceforge.net <pdl-devel@lists.sourceforge.net>;
>> perldl <pdl-gene...@lists.sourceforge.net>
>> *Subject:* [Pdl-devel] conditional inline
>>
>> Hello !
>>
>> I am not sure, but maybe It is possible to do with perl PDL something
>> like this?
>>
>> $ndarray= condition on $ndarray ? assign when true : assign when false
>>
>> for example:
>>
>> $x=zeroes(20)->xlinvals(0,1);
>>
>> $y=(all abs($x-0.5)<0.2)?$x**2:$x;
>>
>> Thanks in advance
>>
>> Regards
>>
>> --
>>
>>
>> Dr. Guillermo P. Ortiz
>> Electromagnetismo Aplicado
>> Dto. Física, Facultad de Ciencias Exactas
>> Universidad Nacional del Nordeste
>> Avda Libertad 5460
>> <https://www.google.com/maps/search/Avda+Libertad+5460?entry=gmail&source=g>,
>> Campus UNNE.
>> W3404AAS Corrientes, Argentina.
>> (+54) 379-4424678 interno 4613
>> gortiz* at *unne edu ar
>>
>>
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