Feature/update layout vis (#496)

* Update layout visualization functions

* Provide an example of layout visualization

* list 23_visaluze_layout in examples.md

---------

Co-authored-by: Rafael M Mudafort <rafmudaf@gmail.com>

docs/examples.md

@@ -86,6 +86,10 @@ impact on wind turbine wakes.
 Load an input file that describes a wind farm with two turbines
 of different types and plot the wake profiles.
 
+### 23_visualize_layout.py
+Use the visualize_layout function to provide diagram visualization
+of a turbine layout within FLORIS
+
 
 ## Optimization
 

examples/23_visualize_layout.py

@@ -0,0 +1,63 @@
+# Copyright 2021 NREL
+
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+# See https://floris.readthedocs.io for documentation
+
+
+import matplotlib.pyplot as plt
+
+from floris.tools import FlorisInterface
+from floris.tools.layout_functions import visualize_layout
+
+
+"""
+This example visualizes a wind turbine layout
+using the visualize_layout function
+"""
+
+# Declare a FLORIS interface
+fi = FlorisInterface("inputs/gch.yaml")
+
+# Assign a 6-turbine layout
+fi.reinitialize(layout_x=[0, 100, 500, 1000, 1200,500], layout_y=[0, 800, 150, 500, 0,500])
+
+# Give turbines specific names
+turbine_names = ['T01', 'T02','T03','S01','X01', 'X02']
+
+# Declare a 4-pane plot
+fig, axarr = plt.subplots(2,2, sharex=True, sharey=True, figsize=(14,10))
+
+# Show the layout with all defaults
+
+# Default visualization
+ax = axarr[0,0] 
+visualize_layout(fi, ax=ax)
+ax.set_title('Default visualization')
+
+# With wake lines
+ax = axarr[0,1] 
+visualize_layout(fi, ax=ax, show_wake_lines=True)
+ax.set_title('Show wake lines')
+
+# Limit wake lines and use provided
+ax = axarr[1,0] 
+visualize_layout(fi, ax=ax, show_wake_lines=True, lim_lines_per_turbine=2, turbine_names=turbine_names)
+ax.set_title('Show only nearest 2, use provided names')
+
+# Show rotors and use black and white
+ax = axarr[1,1] 
+visualize_layout(fi, ax=ax, show_wake_lines=True, lim_lines_per_turbine=2, plot_rotor=True, black_and_white=True)
+ax.set_title('Plot rotors and use black and white option')
+
+
+
+plt.show()