Added test.

tests/test_Calculations_size_distributions.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Sun Nov 24 00:07:14 2024
+
+@author: alex
+"""
+
+
+import unittest
+
+
+class TestCalc(unittest.TestCase):
+    def test_lognormal_number_distribution_log_scale(self):
+        import numpy as np
+        from pathlib import Path
+        import math
+        import sys
+        sys.path.insert(0, str(Path(__file__).parents[2]))
+        from as_tools.Calculations import size_distribution as sd
+
+        particle_diameter = np.geomspace(1e-3, 10, 500)  # µm
+
+        number_size_distribution_nucleation = sd.lognormal_number_distribution_log_scale(
+            number_concentration=7100,
+            standard_deviation=np.exp(0.232),
+            median_particle_diameter=0.0117,
+            particle_diameter=particle_diameter)
+
+        # test for the number of particles, the area under dNdlogdp should be the total
+        # number concentration
+        dlogdp = np.diff(np.log10(particle_diameter)).mean()
+        number_concentration_nucleation = (number_size_distribution_nucleation
+                                           * dlogdp).sum()
+        result = math.isclose(7100, number_concentration_nucleation)
+        self.assertTrue(result)