Thanks!  I will have to study this example a bit more closely.

There have already been other Python to PDL tutorial attempts on Perl
Monks. For example: https://www.perlmonks.org/?node_id=1213987

It might make it a bit easier for newcomers to get oriented.  Would
anyone object to including such a tutorial into the PDL documents
and/or website, once it is compiled and edited?



On Sat, Jul 13, 2019 at 8:45 PM Luis Mochan <[email protected]> wrote:
>
> How about
>
>    pdl> $a=pdl(1,2,3)
>
>    pdl> p pdl($a(*3),$a(:,*3))->flat
>    [1 1 1 2 2 2 3 3 3 1 2 3 1 2 3 1 2 3]
>    pdl>
>
> though you might prefer
>
>    pdl> p append($a(*3)->flat,$a(:,*3)->flat)
>    [1 1 1 2 2 2 3 3 3 1 2 3 1 2 3 1 2 3]
>
> to avoid problems when the shapes of the intermediate arrays are
> incompatible. The *3 inserts a dummy dimension of size 3 in the first
> place, producing three identical columns, while :,*3 produces a dummy
> dimension of size 3 as the second index, so you produce tree identical
> columns,
>
>    pdl> p $a(*3)
>
>    [
>     [1 1 1]
>     [2 2 2]
>     [3 3 3]
>    ]
>
>    pdl> p $a(:,*3)
>
>    [
>     [1 2 3]
>     [1 2 3]
>     [1 2 3]
>    ]
>
> ->flat makes them 1D and append puts one after the other.
>
>
> Regards,
> Luis
>
>
>
>
> On Sat, Jul 13, 2019 at 02:54:34PM -0400, Robert Ryley wrote:
> > I've been working on translating some NumPY examples into PDL.  There
> > has been some positive reinforcement on Perl Monks as can be seen
> > here:
> >
> > https://www.perlmonks.org/?node_id=1233413
> >
> > I am stuck on the following NumPy example:
> >
> > Q. Create the following pattern without hardcoding. Use only numpy
> > functions and the below input array a.
> >
> > Input:
> > a = np.array([1,2,3])`
> >
> > Desired Output:
> > array([1, 1, 1, 2, 2, 2, 3, 3, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3])
> >
> > Solution
> > np.r_[np.repeat(a, 3), np.tile(a, 3)]
> > #> array([1, 1, 1, 2, 2, 2, 3, 3, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3])
> >
> > Does PDL have something equivalent to NumPy's "tile" function?  I've
> > looked through the docs and do not see anything obvious to solve the
> > problem.
> >
> >
> > _______________________________________________
> > pdl-general mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/pdl-general
> >
>
> --
>
>                                                                   o
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>
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