stevenferrer · May 16, 2022 08:12 · May 16, 2022
diff --git a/interactive_circle_transformation.py b/interactive_circle_transformation.py
@@ -0,0 +1,87 @@
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.widgets import Slider
+
+fig, ax = plt.subplots()
+
+fig.tight_layout()
+ax.set_aspect('equal', adjustable='box')
+ax.set_frame_on(False)
+
+# Cirlce matrix with 2x100 shape
+theta = np.linspace(0, 3 * np.pi, 120)
+radius = 32
+
+# Plot the circle
+def plot_circle(c, style='.'):
+    ax.plot(c[:, 0], c[:, 1], style)
+
+c = np.stack((radius * np.cos(theta), radius*np.sin(theta))).T
+plot_circle(c)
+
+# Set min and max slider vals
+val_min = -32
+val_max = 32
+
+# Make room for slider
+plt.subplots_adjust(bottom=0.35)
+
+# Make sliders
+ax_x1 = plt.axes([0.25, 0.2, 0.65, 0.03])
+x1_slider = Slider(
+    ax=ax_x1,
+    label="x1",
+    valmin=val_min,
+    valmax=val_max,
+    valinit=1,
+)
+
+ax_y1 = plt.axes([0.25, 0.15, 0.65, 0.03])
+y1_slider = Slider(
+    ax=ax_y1,
+    label="y1",
+    valmin=val_min,
+    valmax=val_max,
+    valinit=0,
+)
+
+ax_x2 = plt.axes([0.25, 0.1, 0.65, 0.03])
+x2_slider = Slider(
+    ax=ax_x2,
+    label="x2",
+    valmin=val_min,
+    valmax=val_max,
+    valinit=0,
+)
+
+ax_y2 = plt.axes([0.25, 0.05, 0.65, 0.03])
+y2_slider = Slider(
+    ax=ax_y2,
+    label="y2",
+    valmin=val_min,
+    valmax=val_max,
+    valinit=1,
+)
+
+def on_changed(val):
+    T = np.array([
+        [x1_slider.val, y1_slider.val],
+        [x2_slider.val, y2_slider.val],
+    ])
+
+    c = np.stack((radius * np.cos(theta), radius*np.sin(theta))).T
+    cT = c@T
+
+    ax.clear()
+    plot_circle(c, '-')
+    plot_circle(cT, 'g+')
+
+
+x1_slider.on_changed(on_changed)
+y1_slider.on_changed(on_changed)
+
+x2_slider.on_changed(on_changed)
+y2_slider.on_changed(on_changed)
+
+plt.legend()
+plt.show()