From be9f6b6e8e39a711dcfa7806f894b8ec3ff49ca9 Mon Sep 17 00:00:00 2001
From: Jon Nordby <jononor@gmail.com>
Date: Sun, 27 Apr 2025 21:38:29 +0200
Subject: bindings: Example of using pybind11 with numpy

---
 bindings/.gitignore          |  1 +
 bindings/README.md           | 28 ++++++++++++++++++++++++++++
 bindings/galearn_pdm.cpp     | 29 +++++++++++++++++++++++++++++
 bindings/setup.py            | 22 ++++++++++++++++++++++
 bindings/test_galearn_pdm.py | 16 ++++++++++++++++
 5 files changed, 96 insertions(+)
 create mode 100644 bindings/.gitignore
 create mode 100644 bindings/README.md
 create mode 100644 bindings/galearn_pdm.cpp
 create mode 100644 bindings/setup.py
 create mode 100644 bindings/test_galearn_pdm.py

(limited to 'bindings')

diff --git a/bindings/.gitignore b/bindings/.gitignore
new file mode 100644
index 0000000..140f8cf
--- /dev/null
+++ b/bindings/.gitignore
@@ -0,0 +1 @@
+*.so
diff --git a/bindings/README.md b/bindings/README.md
new file mode 100644
index 0000000..dee8dfc
--- /dev/null
+++ b/bindings/README.md
@@ -0,0 +1,28 @@
+
+# Python module
+
+## Prerequisites
+
+The following packages are needed.
+Install with pip or via OS package manager.
+
+    pybind11
+    numpy
+    setuptools
+
+
+## Building
+
+To build the module
+
+    python setup.py build_ext --inplace
+
+This will produce a shared library (`.so` on Linux) in PWD, that Python can load.
+
+## Test
+
+To use the module, see the .py file
+
+    python test_galearn_pdm.py
+
+
diff --git a/bindings/galearn_pdm.cpp b/bindings/galearn_pdm.cpp
new file mode 100644
index 0000000..9274a01
--- /dev/null
+++ b/bindings/galearn_pdm.cpp
@@ -0,0 +1,29 @@
+#include <pybind11/pybind11.h>
+#include <pybind11/numpy.h>
+
+namespace py = pybind11;
+
+void process(py::array_t<uint8_t> arr1, py::array_t<int16_t> arr2) {
+    // Check shapes or sizes if needed
+    auto buf1 = arr1.request();
+    auto buf2 = arr2.request();
+
+    if (buf1.ndim != 1 || buf2.ndim != 1) {
+        throw std::runtime_error("Only 1D arrays supported");
+    }
+
+    if (buf1.size < buf2.size) {
+        throw std::runtime_error("Input 1 must be same or larger than input 2");
+    }
+
+    // Example: access data
+    uint8_t* in = static_cast<uint8_t*>(buf1.ptr);
+    int16_t* out = static_cast<int16_t*>(buf2.ptr);
+    for (int i=0; i<buf2.size; i++) {
+        out[i] = in[i] + 1;
+    }
+}
+
+PYBIND11_MODULE(galearn_pdm, m) {
+    m.def("process", &process, "Process two numpy arrays (uint8 and int16)");
+}
diff --git a/bindings/setup.py b/bindings/setup.py
new file mode 100644
index 0000000..487949a
--- /dev/null
+++ b/bindings/setup.py
@@ -0,0 +1,22 @@
+from setuptools import setup, Extension
+import pybind11
+import numpy
+
+ext_modules = [
+    Extension(
+        'galearn_pdm',
+        ['galearn_pdm.cpp'],
+        include_dirs=[
+            pybind11.get_include(),
+            numpy.get_include(),
+        ],
+        language='c++',
+    ),
+]
+
+setup(
+    name='galearn',
+    version='0.0.1',
+    ext_modules=ext_modules,
+    zip_safe=False,
+)
diff --git a/bindings/test_galearn_pdm.py b/bindings/test_galearn_pdm.py
new file mode 100644
index 0000000..43cb58e
--- /dev/null
+++ b/bindings/test_galearn_pdm.py
@@ -0,0 +1,16 @@
+
+import galearn_pdm
+import numpy
+
+def test_one():
+    
+    inp = numpy.ones(shape=10, dtype=numpy.uint8)
+    out = numpy.zeros(shape=10, dtype=numpy.int16)    
+
+    galearn_pdm.process(inp, out)
+    print(out)
+    assert out[0] == 2
+    assert out[-1] == 2
+
+if __name__ == '__main__':
+    test_one()
-- 
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