test: Update 2D periodic spline example

Add reproducable randomness and remove matplotlib dependence.

Signed-off-by: Sietze van Buuren <s.van.buuren@gmail.com>

Author: swvanbuuren

cubinterpp/periodic_spline_2d.py

@@ -1,5 +1,6 @@
 """ Periodic spline example in 3D """
 
+import random
 import numpy as np
 import cubinterpp.cubinterpp_py as cubinterpp  # cubinterpp_py is a pybind11 module
 import mlpyqtgraph as mpg
@@ -8,13 +9,14 @@
 @mpg.plotter(projection='orthographic')
 def main():
     """ Interpolation of a torus to demonstrate periodic splines in 2D """
-    nx, ny = 5, 5
+    nx, ny = 9, 9
     tx = np.linspace(0.0, 1.0, nx)
     ty = np.linspace(0.0, 1.0, ny)
     # generate torus points
     r_major = 3.0  # major radius
     r_minor = 1.0  # minor radius
 
+    random.seed(43)
     x = np.zeros((nx, ny))
     y = np.zeros((nx, ny))
     z = np.zeros((nx, ny))
@@ -24,7 +26,10 @@ def main():
             v = 2.0 * np.pi * ty[j]
             x[i, j] = (r_major + r_minor * np.cos(v)) * np.cos(u)
             y[i, j] = (r_major + r_minor * np.cos(v)) * np.sin(u)
-            z[i, j] = r_minor * np.sin(v)
+            if i == nx - 1:
+                z[i, j] = z[0, j]
+            else:
+                z[i, j] = (1.0 + random.randint(-2, +2)/8.0) * r_minor * np.sin(v)
 
     # create periodic splines in 2D
     spline_x = cubinterpp.NaturalPeriodicSpline2D(tx, ty, x)
@@ -44,7 +49,7 @@ def main():
             z_fine[i, j] = spline_z.eval(txi[i], tyi[j])
 
 
-    mpg.figure(title='Periodic Spline Interpolation of a Torus')
+    mpg.figure(title='Periodic Spline Interpolation of a distorted Torus')
     mpg.surf(x_fine, y_fine, z_fine)
     ax = mpg.gca()
     ax.azimuth = 225
@@ -55,6 +60,8 @@ def main():
     yp = y.flatten()
     zp = z.flatten()
     mpg.points3(xp, yp, zp, color=(0.8, 0.1, 0.1, 1), size=5)
+    ax.export('periodic_spline_2d.png')
+
 
 if __name__ == '__main__':
     main()

pyproject.toml

@@ -20,8 +20,7 @@ classifiers = [
 ]
 urls = { Homepage = "https://github.com/swvanbuuren/cubinterpp" }
 dependencies = [
-    "matplotlib>=3.10.8",
-    "mlpyqtgraph==0.11.2",
+    "mlpyqtgraph==0.12.0",
     "scipy==1.17.0",
 ]