Trey Harris wrote:
Yes. This is my fear of hyperoperation being the default for normal
aggregates. Loops--and large, multiply-nested, potentially-infinite
ones--can spring out of code that doesn't look loopy at all. Erm... you
know what I mean. :-)
Karl, do you have any objection to
Karl Glazebrook wrote:
Buddha Buck wrote:
@x = 3 * $y[|i];
It's not as clean as @x = 3 * @y, but it is cleaner context-wise.
And one could argue that:
@x = map 3*^_, @y;
is cleaner yet...
PDL already allows $x = 3*$y
why step backwards?
Exactly. Those other
Damian Conway wrote:
You can't, in serial implementation. But on a parallel architecture
or, better still, on a quantum device, you can run all the computations
in parallel.
I see that. PDL has that as an experimental feature on any ufunc (in
fact on any function that has a signature). It is
Jeremy Howard wrote:
the maximum index of each dimension. A maximum index of '0' would mean that
that dimension is 1 element wide. Therefore '0' can not be special in
reshape(). Therefore we should use '-1'.
-1 is the maximum index for any size in the usual fashion of perl array
indexing.
Jeremy Howard wrote:
To be honest, I don't really get the point of stuff like NumPy's "NewAxis",
so I might be misunderstanding your proposal. But at least for your
It's just another way to specify how implicit loops of a scalar
operation are iterated over array elements (TIMTWTDI). Very
Jeremy Howard wrote:
Removed -language x-post
Wouldn't it be very useful if all of the applicable polymorphic methods
of RFC 159 would be overloadable for nD arrays (arrays becoming
effectively instances of array objects)? I am not sure if this has been
discussed before but I could
://numpy.sourceforge.net/numdoc/HTML/numdoc.html#pgfId-36371
--
Christian Soeller[EMAIL PROTECTED] x2770
Dept. of Physiology U. Auckland School of Medicine
Auckland New Zealand
Jeremy Howard wrote:
Of course they have reasonable meanings for arrays--element-wise operations
(RFC 82):
http://tmtowtdi.perl.org/rfc/82.html
Any operation you can do on a scalar you should be able to do element-wise
on a list, and certainly it's not hard to come up with situations
Quantum::Superpositions provides this in a more flexible way by adding the
'any' and 'all' keywords.
http://search.cpan.org/doc/DCONWAY/Quantum-Superpositions-1.03/lib/Quantum/
Superpositions.pm
One of Damian Conway's many promised RFCs will cover
Buddha Buck wrote:
Tensor or Matrix
Multidimensional list
what should we call it?
I'd vote for matrix myself. It's short and sweet
Fine ;) Just have a section in the elusive overview RFC that defines
what we mean by matrix, e.g. not only 2D objects of linear algebra.
With all these
Jeremy Howard wrote:
The 1st implementation of Perl 6 may not provide all the optimisations we've
come to expect from our data crunching language of choice. For this reason
maybe PDL will continue to exist independently in Perl 6 at least for a
while, although a fair bit of rewriting will be
Jeremy Howard wrote:
I'd rather see the ';' be required, but the '(0..)' not be required, so you
This is not good! There are a lot of routines where it is very useful to
specify a slice as
@a[0]
that should work regardless how many dimensions @a really has. There are
many instances in PDL
Karl Glazebrook wrote:
This also addresses one pain in current PDL which is the
difficulty of multi-dim indexing.
I like it, too ;)
print $a[[0,0,0]];# literal ref list
print $a[0;0;0]; # literal singleton ; list
print $a[[$y,$y,$y]]; # variable-based ref list
print
Buddha Buck wrote:
RFC X+2: Retrieving Matrix dimensions
Present @#matrix as analogous to $#array
Discuss what $#matrix should return, as well as @#array
What is @matrix in scaler context? (undef, anyone?)
Number of elements? For sparse matrices number of non-zero elements?
A
Buddha Buck wrote:
Would you go for:
@a[$first;*];
@a[*;$last];
@a[$first;*;$last]?
Say yes, and I'll add it tonight!
Nice! I'd go as far as implying a trailing ';*' if omitted.
I'm unsure if @a[*;$middle;*] has any reasonable interpretation.
Probably just croak. Unless somebody
Jeremy Howard wrote:
Baris wrote:
First of all I know that perl syntax has limitations and I understand why
the reasons of the new syntax proposals. And I think the syntax proposals
are pretty good if you accept the syntax limitations. I don't think any of
them do consider that if
Jeremy Howard wrote:
14,17;...20,29). What if we created a new operator ';' that works within a
list that creates a cartesian product?:
(10:20:2; 11:30:3); # Cartesian product of 10:20:2 and 11:30:3 as a LOL
A possible approach. Two issues: (1) others might argue that we should
use a
Jeremy Howard wrote:
Ditto. As I said yesterday, my current preferred option is that a list ref
of list refs will also support a multidimensional indexing syntax.
Furthermore, if it has a single basic data type and is declared ':compact'
it should be stored in a contiguous block of memory.
Baris wrote:
My motivation was to give more freedom to the developers of pdl so that
they can freely create the syntax without worrying about the workarounds.
Matlab, in my opinion, is much more natural to code than current pdl.
It'd be interesting to hear what you dislike in particular.
Damian Conway wrote:
Regardless, you can already do this in perl 5, and will undoubtedly
be able to do it in perl 6, with source filters. (If Damian can
write perl that looks like Latin or Klingon, then python ought to
be simple... :)
I have a module
Dan Sugalski wrote:
Because source filters are:
1) Relatively new (5.005 IIRC, but I could be mis-remembering)
2) A bloody pain in the neck to write
Lots of things could use 'em if they were easier to do. That's one of the
goals of perl 6, I think.
Are there any docs in perl 5.6
Doug Hunt wrote:
What I meant to say (but failed, alas) was that I support the idea for a
new perl variable type called compact array:
$foo -- scalar
@foo -- array
%foo -- hash
^foo -- compact array (or whatever notation)
I seem to remember that ^ was in the process of being
Karl Glazebrook wrote:
Consider
@x[10:20, 20:40:2, 30:50]
This ALMOST works in the current Perl. @x gives array context,
then the , produces a list.
I see a number of problems with the current (scalar) PDL objects being
turned (essentially) into perl arrays in perl6.
1) How do you
Jeremy Howard wrote:
Basically, I want to be able to create a list ref of list refs, specify a
data type (eg 'int') and attributes of ':compact' or ':sparse', and have the
As Dan Sugalski suggested it seems not a good idea to bring in the list
of list ref into the proposal. Why does it have
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