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Bug 1433

Summary: horizontal/vertical stacking for matrix assembly
Product: Eigen Reporter: Gael Guennebaud <gael.guennebaud>
Component: Core - generalAssignee: Nobody <eigen.nobody>
Status: CONFIRMED ---    
Severity: Feature Request CC: chtz, gael.guennebaud, jacob.benoit.1
Priority: Normal    
Version: 3.4 (development)   
Hardware: All   
OS: All   
Whiteboard:
Bug Depends on:    
Bug Blocks: 1420, 1608    

Description Gael Guennebaud 2017-06-06 09:10:55 UTC
Here is an interesting proposal for matrix assembly via horizontal and vertical stacking: https://forum.kde.org/viewtopic.php?f=74&t=140012

It works with C++11.

Still need to debate on final API, implement proper unit tests, docs, etc.
Comment 1 Gael Guennebaud 2017-06-06 13:24:06 UTC
and for the record, here is the first attempt from the same author: https://forum.kde.org/viewtopic.php?f=74&t=123881&p=375217&hilit=initializer_list#p375217
Comment 2 Christoph Hertzberg 2017-07-18 12:33:58 UTC
Very interesting indeed. And probably the closest we can get to Matlab-style [,;] matrix stacking.
I always found the << operator inconvenient, as it requires to resize the target in advance, and makes inline usage of stacked matrices very ugly.
Maybe it would even be possible to support C++03 (for a limited number of concatenated matrices). OTOH, maybe Eigen3.4 will be a good time to start giving up C++03 support (at least not force new features into it).
Comment 3 Nobody 2019-12-04 17:01:34 UTC
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