Merge pull request #114 from kyri-petrou/feature/vectorize-power-output

Vectorize _get_power_output calculations

Author: uvchik

windpowerlib/power_output.py

@@ -286,18 +286,22 @@ def _get_power_output(
     :numpy:`numpy.array`
         Electrical power output of the wind turbine in W.
     """
-    power_output = np.empty(len(wind_speed), dtype=np.float)
+    # Calculate the power curves for each timestep using vectors
+    # NOTE: power_curves_per_ts.shape = [len(wind_speed), len(density)]
+    power_curves_per_ts = (
+        (1.225 / density).reshape(-1, 1)
+        ** np.interp(power_curve_wind_speeds, [7.5, 12.5], [1 / 3, 2 / 3])
+    ) * power_curve_wind_speeds
 
-    for i in range(len(wind_speed)):
-        power_output[i] = np.interp(
-            wind_speed[i],
-            power_curve_wind_speeds
-            * (1.225 / density[i])
-            ** (
-                np.interp(power_curve_wind_speeds, [7.5, 12.5], [1 / 3, 2 / 3])
-            ),
-            power_curve_values,
-            left=0,
-            right=0,
+    # Create the interpolation function
+    def interp_func(w_speed, p_curves):
+        return np.interp(
+            w_speed, p_curves, power_curve_values, left=0, right=0
         )
+
+    # Calculate the power output by mapping the arrays to the interp function
+    power_output = np.array(
+        list(map(interp_func, wind_speed, power_curves_per_ts))
+    )
+
     return power_output