Re: [eigen] eigen expression template classes

[Gael Guennebaud <gael.guennebaud@xxxxxxxxx>]

Also note that the _expression_/evaluator engine in Eigen/Core is different that the one in Eigen/CXX11/Tensor, so depending what you meant by "Eigen" you will have at look at different places. In Core main expressions are:

CwiseNullaryOp<>

CwiseUnaryOp<>

CwiseUnaryViewOp<>

CwiseBinaryOp<>

Block<>

IndexedView<>

Transpose<>

Reverse<>

Replicate<>

Product<>

PartialRedux<>

plus some "special"  ones:

TriangularView<>

SelfadjointView<>

Inverse<>

Solver<>

And leafs are:

Matrix

Array

Ref

Map

Then comes the evaluator<> which is specialized for each _expression_ in CoreEvaluators.h, but there is no generic mechanisms to go through an _expression_ tree and do some processing.

gael

On Mon, Sep 17, 2018 at 1:57 PM Christoph Hertzberg <chtz@xxxxxxxxxxxxxxxxxxxxxxxx> wrote:

Hi!

You can get a bit more internal documentation, if you build the
documentation yourself with EIGEN_INTERNAL_DOCUMENTATION activated:

$ cd path_of_build_dir
$ cmake -DEIGEN_INTERNAL_DOCUMENTATION=ON path_to_eigen
$ make doc -j8

This documentation is likely far from perfect (see also
http://eigen.tuxfamily.org/bz/show_bug.cgi?id=138)

Also, there is some (old and at least partially outdated) documentation
in the wiki, e.g.:
http://eigen.tuxfamily.org/index.php?title=Expression_templates
http://eigen.tuxfamily.org/index.php?title=Working_notes_-_Expression_evaluator

So in the end, you will need to look into the source and ask questions
either here, on IRC or stackoverflow -- ideally also propose possible
improvements (here or on http://eigen.tuxfamily.org/bz, or with
Pull-requests).


Hope that helped a little,
Christoph




On 2018-09-17 12:23, Brook Milligan wrote:
> Hi,
>
> I would like to integrate eigen _expression_ templates with another _expression_ template library.  It would seem that this is possible if I understand the core types used to represent eigen expressions.  However, as far as I can tell, those types of not documented in the eigen documentation.  Nevertheless, it seems that there may be a (small?) set of those types.
>
> Can you point me to the specific classes that are used to represent eigen expressions?
>
> Have you ever tried to integrate eigen expressions with another _expression_ template library?
>
> Do you have any suggestions that would help guide such an effort?
>
> Thank you very much for your help.
>
> Cheers,
> Brook
>
>
>
>
>

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