Merge branch '1-define-a-function-to-take-a-numpy-array' into 'master'

Add C++ function to calculate sum of input vector

Closes #1

See merge request !2

src/main.cpp

 #include <pybind11/pybind11.h>
+#include <pybind11/stl.h> // This header is needed to work with STL containers like std::vector
 
 // #define VERSION_INFO 1.0
 
@@ -13,6 +14,25 @@ double multiply(double i, double j) {
     return i * j;
 }
 
+double sum_array(const std::vector<double> &arr) {
+    double sum = 0;
+    for (double num : arr) {
+        sum += num;
+    }
+    return sum;
+}
+
+double sum_2d_array(const std::vector<std::vector<double>> &arr) {
+    double sum = 0;
+    for (const auto &row : arr) {
+        for (double num : row) {
+            sum += num;
+        }
+    }
+    return sum;
+}
+
+
 namespace py = pybind11;
 
 PYBIND11_MODULE(_core, m) {
@@ -46,6 +66,9 @@ PYBIND11_MODULE(_core, m) {
         Some other explanation about the subtract function.
     )pbdoc",py::arg("i"), py::arg("j"));
 
+    m.def("sum_array", &sum_array, "Calculate the sum of elements in an array");
+    m.def("sum_2d_array", &sum_2d_array, "Calculate the sum of elements in a 2D array");
+
 #ifdef VERSION_INFO
     m.attr("__version__") = MACRO_STRINGIFY(VERSION_INFO);
 #else

src/pybind_example/__init__.py

 from __future__ import annotations
 
-from ._core import __doc__, __version__, add, subtract, multiply
+from ._core import (
+    __doc__,
+    __version__,
+    add,
+    subtract,
+    multiply,
+    sum_array,
+    sum_2d_array,
+)
 
-__all__ = ["__doc__", "__version__", "add", "subtract"]
+__all__ = [
+    "__doc__",
+    "__version__",
+    "add",
+    "subtract",
+    "multiply",
+    "sum_array",
+    "sum_2d_array",
+]

tests/test_basic.py

 from __future__ import annotations
 
 import pybind_example as m
+import numpy as np
 
 
 def test_version():
@@ -13,3 +14,23 @@ def test_add():
 
 def test_sub():
     assert m.subtract(1, 2) == -1
+
+
+def test_sum_array_numpy_array_1D_float():
+    array = np.asarray([1.0, 1.0, 2.0, 1.0, 1.0])
+    assert m.sum_array(array) == 6
+
+
+def test_sum_array_numpy_list_1D_float():
+    list_ = [1.0, 1.0, 2.0, 1.0, 1.0]
+    assert m.sum_array(list_) == 6
+
+
+def test_sum_array_numpy_array_1D_int():
+    array = np.ones(10)
+    assert m.sum_array(array) == 10
+
+
+def test_sum_array_numpy_array_2D_float():
+    array = np.arange(9).reshape((3,3))
+    assert m.sum_2d_array(array) == np.sum(array)