Investigate removal of custom math/*Matrix;

[breznak]

There is a huge ammount of code in math/*Matrix that is old, unmaintained and quite untested. Propose removal and replacement :

• replace with Connections
• or Eigen Eigen speed #42
• or keep only the SparseBinaryMatrix

Look at the problem and proposed order of progress:

grep -R 'Matrix' src/nupic/math/ | cut -d: -f1 |sort -u

• src/nupic/math/Math.hpp
• src/nupic/math/ArrayAlgo.hpp -- maybe most of its methods will be removed?
• src/nupic/math/DenseMatrix.hpp -- only one user SDRClassifier, replace with sparse & rm first SDR Classifier without densematrix #170 Sparsematrix removal 2 #169
• src/nupic/math/NearestNeighbor.hpp -- NN does not have to be in a HTM codebase
• src/nupic/math/SparseBinaryMatrix.hpp -- heavily used in SP Spatial Pooler: investigate using Connections as backend #93 , Sparsematrix removal 2 #169
• algorithms/CondProbTable -- rm too? Uses:
  • src/nupic/math/SparseMatrix01.hpp -- not used, rm
• src/nupic/math/SparseMatrix.hpp -- huge, untested, suprisingly not a base of SparseBinaryM Sparsematrix removal 2 #169
  • used in ArrayAlgo, DenseMatrix, SpatialPooler
• src/nupic/math/SparseMatrixAlgorithms.hpp -- not used, rm
• src/nupic/math/SparseMatrixConnections.hpp -- not used, rm
  • src/nupic/math/SegmentMatrixAdapter.hpp -- used only in SMConn
    • py_SegmentSparseMatrix
• src/nupic/math/SparseRLEMatrix.hpp -- not used, rm
• src/nupic/math/SparseTensor.hpp -- not sure how needed for Py - implemented (but reverted) here: bfb58df , Sparsematrix removal 2 #169
  • Domain
  • Index
  • PyBindSparseTensor
• math/Math.hpp:Gaussian_2D -- not used, further cleanup Math.hpp

Related:

• Spatial Pooler: investigate using Connections as backend #93 SP on Connections

Prerequisities:

• c++ speed tests Real-life benchmark: Hotgym example using C++ algorithms #30
• validate Python nupic still compatible with this nupic.core Validate python nupic is still compatible with our nupic.core c++ bindings #137

[dkeeney]

Hmmm, if that is exposed to Python code it might be used more than you think.

[breznak]

f that is exposed to Python code it might be used more than you think.

Good call, but no. SparseMatrix is used everywhere, Dense only in that one class.
I'd like to:

• rid off Dense
• (optionally) replace Sparse with Eigen::SparseMatrix

[dkeeney]

• rid off Dense

Yes.

• (optionally) replace Sparse with Eigen::SparseMatrix

Don't know enough about Eigen to tell you if it is a good idea.

[breznak]

Reopening to continue further cleanup after #93
Next target: bfb58df

[breznak]

I will try to resume this work and rm further more, given #153 is merged now.