From 47e5ac79af3a354358515c0213b28848f878fde6 Mon Sep 17 00:00:00 2001
From: Marc Glisse <marc.glisse@inria.fr>
Date: Wed, 6 May 2020 22:59:36 +0200
Subject: Reimplement the bottleneck python wrapper with pybind11

---
 src/python/gudhi/bottleneck.cc | 51 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 src/python/gudhi/bottleneck.cc

(limited to 'src/python/gudhi/bottleneck.cc')

diff --git a/src/python/gudhi/bottleneck.cc b/src/python/gudhi/bottleneck.cc
new file mode 100644
index 00000000..577e5e0b
--- /dev/null
+++ b/src/python/gudhi/bottleneck.cc
@@ -0,0 +1,51 @@
+/*    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 <gudhi/Bottleneck.h>
+
+#include <pybind11_diagram_utils.h>
+
+double bottleneck(Dgm d1, Dgm d2, double epsilon)
+{
+  // I *think* the call to request() has to be before releasing the GIL.
+  auto diag1 = numpy_to_range_of_pairs(d1);
+  auto diag2 = numpy_to_range_of_pairs(d2);
+
+  py::gil_scoped_release release;
+
+  return Gudhi::persistence_diagram::bottleneck_distance(diag1, diag2, epsilon);
+}
+
+PYBIND11_MODULE(bottleneck, m) {
+      m.attr("__license__") = "GPL v3";
+      m.def("bottleneck_distance", &bottleneck,
+          py::arg("diagram_1"), py::arg("diagram_2"),
+          py::arg("e") = (std::numeric_limits<double>::min)(),
+          R"pbdoc(
+    This function returns the point corresponding to a given vertex.
+
+    :param diagram_1: The first diagram.
+    :type diagram_1: vector[pair[double, double]]
+    :param diagram_2: The second diagram.
+    :type diagram_2: vector[pair[double, double]]
+    :param e: If `e` is 0, this uses an expensive algorithm to compute the
+        exact distance.
+        If `e` is not 0, it asks for an additive `e`-approximation, and
+        currently also allows a small multiplicative error (the last 2 or 3
+        bits of the mantissa may be wrong). This version of the algorithm takes
+        advantage of the limited precision of `double` and is usually a lot
+        faster to compute, whatever the value of `e`.
+
+        Thus, by default, `e` is the smallest positive double.
+    :type e: float
+    :rtype: float
+    :returns: the bottleneck distance.
+    )pbdoc");
+}
-- 
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