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Diffstat (limited to 'src/python/include/pybind11_diagram_utils.h')
-rw-r--r-- | src/python/include/pybind11_diagram_utils.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/python/include/pybind11_diagram_utils.h b/src/python/include/pybind11_diagram_utils.h new file mode 100644 index 00000000..d9627258 --- /dev/null +++ b/src/python/include/pybind11_diagram_utils.h @@ -0,0 +1,39 @@ +/* This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. + * See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. + * Author(s): Marc Glisse + * + * Copyright (C) 2020 Inria + * + * Modification(s): + * - YYYY/MM Author: Description of the modification + */ + +#include <pybind11/pybind11.h> +#include <pybind11/numpy.h> + +#include <boost/range/counting_range.hpp> +#include <boost/range/adaptor/transformed.hpp> + +namespace py = pybind11; +typedef py::array_t<double> Dgm; + +// Get m[i,0] and m[i,1] as a pair +static auto pairify(void* p, ssize_t h, ssize_t w) { + return [=](ssize_t i){ + char* birth = (char*)p + i * h; + char* death = birth + w; + return std::make_pair(*(double*)birth, *(double*)death); + }; +} + +inline auto numpy_to_range_of_pairs(py::array_t<double> dgm) { + py::buffer_info buf = dgm.request(); + // shape (n,2) or (0) for empty + if((buf.ndim!=2 || buf.shape[1]!=2) && (buf.ndim!=1 || buf.shape[0]!=0)) + throw std::runtime_error("Diagram must be an array of size n x 2"); + // In the case of shape (0), avoid reading non-existing strides[1] even if we won't use it. + ssize_t stride1 = buf.ndim == 2 ? buf.strides[1] : 0; + auto cnt = boost::counting_range<ssize_t>(0, buf.shape[0]); + return boost::adaptors::transform(cnt, pairify(buf.ptr, buf.strides[0], stride1)); + // Be careful that the returned range cannot contain references to dead temporaries. +} |