This is an integration with the Eigen library, based on the documentation of pybind
This is an optional dependency and it can be enabled by
OPEN_SPIEL_BUILD_WITH_EIGEN global variable (see install.sh).
Use the header eigen/pyeig.h to get basic Matrix and Vector types. The
types in this header file are tested for compatibility with numpy. Other Eigen
types might not be compatible (due to memory layout), so be careful if you use
them in the code and you'd like to expose them to Python.
There is an integration test with pybind: it creates an internal namespace
open_spiel::eigen_test, which is then invoked as part of the Python test suite
by loading module pyspiel_eigen.
Things to keep in mind.
- Numpy stores vectors as 1D shape. Eigen however stores vectors as 2D shape,
i.e. a matrix with one dimension equal to one. The default implementation in
Eigen sets the column dimension to be equal to 1. However, to be compatible
with numpy's memory layout, we need to use row layout, so by default the
row dimension is equal to 1. See
test_square_vector_elements