rewrite derivatives of triangle wave

Author: SBlokhuizen

waveform_editor/tendencies/periodic/triangle_wave.py

@@ -1,3 +1,5 @@
+from typing import Optional
+
 import numpy as np
 from param import depends
 
@@ -7,7 +9,9 @@
 class TriangleWaveTendency(PeriodicBaseTendency):
     """A tendency representing a triangle wave."""
 
-    def generate(self, time=None):
+    def get_value(
+        self, time: Optional[np.ndarray] = None
+    ) -> tuple[np.ndarray, np.ndarray]:
         """Generate time and values based on the tendency. If no time array is provided,
         a time array will be created from the start to the end of the tendency, where
         time points are defined for every peak and trough in the tendency.
@@ -23,21 +27,17 @@ def generate(self, time=None):
         values = self._calc_triangle_wave(time)
         return time, values
 
-    def get_start_value(self) -> float:
-        """Returns the value of the tendency at the start."""
-        return self._calc_triangle_wave(self.start)
-
-    def get_end_value(self) -> float:
-        """Returns the value of the tendency at the end."""
-        return self._calc_triangle_wave(self.end)
+    def get_derivative(self, time: np.ndarray) -> np.ndarray:
+        """Get the derivative values on the provided time array.
 
-    def get_derivative_start(self) -> float:
-        """Returns the derivative of the tendency at the start."""
-        return self._calc_triangle_derivative(self.start)
+        Args:
+            time: The time array on which to generate points.
 
-    def get_derivative_end(self) -> float:
-        """Returns the derivative of the tendency at the end."""
-        return self._calc_triangle_derivative(self.end)
+        Returns:
+            numpy array containing the derivatives
+        """
+        derivatives = self._calc_triangle_derivative(time)
+        return derivatives
 
     def _calc_triangle_wave(self, time):
         """Calculates the point of the triangle wave at a given time point or
@@ -63,8 +63,8 @@ def _calc_triangle_derivative(self, time):
             The derivative of the triangle wave.
         """
         is_rising = self._calc_phase(time) % (2 * np.pi) > np.pi
-
-        return self.rate if is_rising else -self.rate
+        rate = 4 * self.frequency * self.amplitude
+        return np.where(is_rising, rate, -rate)
 
     def _calc_phase(self, time):
         """Calculates the phase of the triangle wave at a given time point or
@@ -78,11 +78,6 @@ def _calc_phase(self, time):
         """
         return 2 * np.pi * self.frequency * (time - self.start) + self.phase - np.pi / 2
 
-    @depends("values_changed", watch=True)
-    def _update_rate(self):
-        """Calculates the rate of change."""
-        self.rate = 4 * self.frequency * self.amplitude
-
     def _calc_minimal_triangle_wave(self):
         """Calculates the time points at which the peaks and troughs of the triangle
         wave occur, which are minimally required to represent the triangle wave fully.