From 8dfe698316fb7b4d7cc269d1770ab0086a258108 Mon Sep 17 00:00:00 2001
From: kumar10725 <48549256+kumar10725@users.noreply.github.com>
Date: Tue, 15 Sep 2020 16:46:57 +0800
Subject: [PATCH 1/4] Speed Improvement in "power_curve_density_correction"

Convert Pandas Series to Numpy Array for faster numpy interpolation (np.interp) on larger dataset.
---
 windpowerlib/power_output.py | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/windpowerlib/power_output.py b/windpowerlib/power_output.py
index d254200c..41a161f9 100644
--- a/windpowerlib/power_output.py
+++ b/windpowerlib/power_output.py
@@ -172,14 +172,11 @@ def power_curve(
 
 
 def power_curve_density_correction(
-    wind_speed, power_curve_wind_speeds, power_curve_values, density
-):
+    wind_speed, power_curve_wind_speeds, power_curve_values, density):
     r"""
     Calculates the turbine power output using a density corrected power curve.
-
     This function is carried out when the parameter `density_correction` of an
     instance of the :class:`~.modelchain.ModelChain` class is True.
-
     Parameters
     ----------
     wind_speed : :pandas:`pandas.Series<series>` or numpy.array
@@ -192,21 +189,17 @@ def power_curve_density_correction(
         `power_curve_wind_speeds`.
     density : :pandas:`pandas.Series<series>` or numpy.array
         Density of air at hub height in kg/m³.
-
     Returns
     -------
     :pandas:`pandas.Series<series>` or numpy.array
         Electrical power output of the wind turbine in W.
         Data type depends on type of `wind_speed`.
-
     Notes
     -----
     The following equation is used for the site specific power curve wind
     speeds [1]_ [2]_ [3]_:
-
     .. math:: v_{site}=v_{std}\cdot\left(\frac{\rho_0}
                        {\rho_{site}}\right)^{p(v)}
-
     with:
         .. math:: p=\begin{cases}
                       \frac{1}{3} & v_{std} \leq 7.5\text{ m/s}\\
@@ -214,19 +207,15 @@ def power_curve_density_correction(
                       \text{ m/s}<v_{std}<12.5\text{ m/s}\\
                       \frac{2}{3} & \geq 12.5 \text{ m/s}
                     \end{cases},
-
         v: wind speed [m/s], :math:`\rho`: density [kg/m³]
-
     :math:`v_{std}` is the standard wind speed in the power curve
     (:math:`v_{std}`, :math:`P_{std}`),
     :math:`v_{site}` is the density corrected wind speed for the power curve
     (:math:`v_{site}`, :math:`P_{std}`),
     :math:`\rho_0` is the ambient density (1.225 kg/m³)
     and :math:`\rho_{site}` the density at site conditions (and hub height).
-
     It is assumed that the power output for wind speeds above the maximum
     and below the minimum wind speed given in the power curve is zero.
-
     References
     ----------
     .. [1] Svenningsen, L.: "Power Curve Air Density Correction And Other
@@ -238,7 +227,6 @@ def power_curve_density_correction(
             Variable Scale Simulation Model for Windpower based on the
             Georeferenced Installation Register of Germany". Master's Thesis
             at Reiner Lemoine Institute, 2014, p. 13
-
     """
     if density is None:
         raise TypeError(
@@ -246,6 +234,19 @@ def power_curve_density_correction(
             + "density corrected power curve density at hub "
             + "height is needed."
         )
+
+    #NOTE : CHANGES ARE MADE HERE FOR SPEED IMPROVEMENT
+    # create a flag for pandas Series type
+    Panda_series = False
+    
+    if isinstance(wind_speed, pd.Series):
+        #save the indexes for later conversion to pd.Series
+        indexes = wind_speed.index
+        # change the wind speed Series to numpy array 
+        wind_speed = wind_speed.values
+        # Set the panda flag True 
+        Panda_series = True
+
     power_output = [
         (
             np.interp(
@@ -266,10 +267,10 @@ def power_curve_density_correction(
     ]
 
     # Power_output as pd.Series if wind_speed is pd.Series (else: np.array)
-    if isinstance(wind_speed, pd.Series):
+    if Panda_series: #use the flag to check
         power_output = pd.Series(
             data=power_output,
-            index=wind_speed.index,
+            index=indexes, # Use previously saved indexes
             name="feedin_power_plant",
         )
     else:

From 7c386a09033c9222f40a59a4e534f7e55972b531 Mon Sep 17 00:00:00 2001
From: stickler-ci <support@stickler-ci.com>
Date: Tue, 15 Sep 2020 10:05:43 +0000
Subject: [PATCH 2/4] Fixing style errors.

---
 windpowerlib/power_output.py | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/windpowerlib/power_output.py b/windpowerlib/power_output.py
index 41a161f9..d0277893 100644
--- a/windpowerlib/power_output.py
+++ b/windpowerlib/power_output.py
@@ -172,7 +172,8 @@ def power_curve(
 
 
 def power_curve_density_correction(
-    wind_speed, power_curve_wind_speeds, power_curve_values, density):
+    wind_speed, power_curve_wind_speeds, power_curve_values, density
+):
     r"""
     Calculates the turbine power output using a density corrected power curve.
     This function is carried out when the parameter `density_correction` of an
@@ -235,16 +236,16 @@ def power_curve_density_correction(
             + "height is needed."
         )
 
-    #NOTE : CHANGES ARE MADE HERE FOR SPEED IMPROVEMENT
+    # NOTE : CHANGES ARE MADE HERE FOR SPEED IMPROVEMENT
     # create a flag for pandas Series type
     Panda_series = False
-    
+
     if isinstance(wind_speed, pd.Series):
-        #save the indexes for later conversion to pd.Series
+        # save the indexes for later conversion to pd.Series
         indexes = wind_speed.index
-        # change the wind speed Series to numpy array 
+        # change the wind speed Series to numpy array
         wind_speed = wind_speed.values
-        # Set the panda flag True 
+        # Set the panda flag True
         Panda_series = True
 
     power_output = [
@@ -267,10 +268,10 @@ def power_curve_density_correction(
     ]
 
     # Power_output as pd.Series if wind_speed is pd.Series (else: np.array)
-    if Panda_series: #use the flag to check
+    if Panda_series:  # use the flag to check
         power_output = pd.Series(
             data=power_output,
-            index=indexes, # Use previously saved indexes
+            index=indexes,  # Use previously saved indexes
             name="feedin_power_plant",
         )
     else:

From 11a321011cdb253742dab5044670e9e13f56abcb Mon Sep 17 00:00:00 2001
From: Kumar Shivam <48549256+kumar10725@users.noreply.github.com>
Date: Tue, 15 Sep 2020 21:38:59 +0800
Subject: [PATCH 3/4] Update power_output.py

---
 windpowerlib/power_output.py | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/windpowerlib/power_output.py b/windpowerlib/power_output.py
index d0277893..684009f7 100644
--- a/windpowerlib/power_output.py
+++ b/windpowerlib/power_output.py
@@ -236,17 +236,16 @@ def power_curve_density_correction(
             + "height is needed."
         )
 
-    # NOTE : CHANGES ARE MADE HERE FOR SPEED IMPROVEMENT
-    # create a flag for pandas Series type
-    Panda_series = False
-
+    # Convert pandas.Series to a numpy array to speed up the interpolation below.    
     if isinstance(wind_speed, pd.Series):
         # save the indexes for later conversion to pd.Series
-        indexes = wind_speed.index
+        wind_speed_indexes = wind_speed.index
         # change the wind speed Series to numpy array
         wind_speed = wind_speed.values
-        # Set the panda flag True
-        Panda_series = True
+        # Set the panda series flag True
+        panda_series = True
+    else:
+        panda_series = False
 
     power_output = [
         (
@@ -268,10 +267,10 @@ def power_curve_density_correction(
     ]
 
     # Power_output as pd.Series if wind_speed is pd.Series (else: np.array)
-    if Panda_series:  # use the flag to check
+    if panda_series:  # use the flag to check if the data should be converted back to pandas.Series
         power_output = pd.Series(
             data=power_output,
-            index=indexes,  # Use previously saved indexes
+            index=wind_speed_indexes,  # Use previously saved wind speed indexes
             name="feedin_power_plant",
         )
     else:

From 7c497637e7cacfb90cb8647e0395512fbb3164b6 Mon Sep 17 00:00:00 2001
From: stickler-ci <support@stickler-ci.com>
Date: Tue, 15 Sep 2020 13:39:05 +0000
Subject: [PATCH 4/4] Fixing style errors.

---
 windpowerlib/power_output.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/windpowerlib/power_output.py b/windpowerlib/power_output.py
index 684009f7..8b1425e7 100644
--- a/windpowerlib/power_output.py
+++ b/windpowerlib/power_output.py
@@ -236,7 +236,7 @@ def power_curve_density_correction(
             + "height is needed."
         )
 
-    # Convert pandas.Series to a numpy array to speed up the interpolation below.    
+    # Convert pandas.Series to a numpy array to speed up the interpolation below.
     if isinstance(wind_speed, pd.Series):
         # save the indexes for later conversion to pd.Series
         wind_speed_indexes = wind_speed.index
@@ -267,7 +267,9 @@ def power_curve_density_correction(
     ]
 
     # Power_output as pd.Series if wind_speed is pd.Series (else: np.array)
-    if panda_series:  # use the flag to check if the data should be converted back to pandas.Series
+    if (
+        panda_series
+    ):  # use the flag to check if the data should be converted back to pandas.Series
         power_output = pd.Series(
             data=power_output,
             index=wind_speed_indexes,  # Use previously saved wind speed indexes