First pass at export function, fix vmin and vmax

hnn_core/viz.py

@@ -1294,7 +1294,7 @@ def get_voltages(self):
 
         vsec_array = np.vstack(vsec_list)
         vsec_array = (vsec_array - self.vmin) / (self.vmax - self.vmin)
-        return np.vstack(vsec_list)
+        return vsec_array
 
     def update_section_voltages(self, t_idx):
         color_list = self.color_array[:, t_idx]
@@ -1322,6 +1322,15 @@ def _update_axes(self):
 
         self.ax.view_init(self._elev, self._azim)
 
+    def export_movie(self, fname, dpi=300):
+        import matplotlib.animation as animation
+        ani = animation.FuncAnimation(
+            self.fig, self.set_time_idx, len(self.times) - 1, interval=30)
+
+        writer = animation.writers['ffmpeg'](fps=30)
+        ani.save(fname, writer=writer, dpi=dpi)
+        return ani
+
     # Axis limits
     @property
     def xlim(self):
@@ -1410,6 +1419,10 @@ def time_idx(self, time_idx):
         self._time_idx = time_idx
         self.update_section_voltages(self._time_idx)
 
+    # Necessary for making animations
+    def set_time_idx(self, time_idx):
+        self.time_idx = time_idx
+
     # Background color and voltage colormaps
     @property
     def bg_color(self):