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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Wilson-Devinney Style Meshing
NOTE
Step1:  As always, let's do imports and initialize a logger and a new bundle.  See Building a System for more details.
Step2:  Changing Meshing Options
Next we need to add compute options and change the mesh_style for all stars from 'marching' to 'wd'
Step3:  Adding Datasets
Next let's add a mesh dataset so that we can plot our Wilson-Devinney style meshes
Step4:  Running Compute
Step5:  Plotting
Step6:  Now let's zoom in so we can see the layout of the triangles.  Note that Wilson-Devinney uses trapezoids, but since PHOEBE uses triangles, we take each of the trapezoids and split it into two triangles.
Step7:  And now looking down from above.  Here you can see the gaps between the surface elements (and you can also see some of the subdivision that's taking place along the limb).
Step8:  And see which elements are visible at the current time.  This defaults to use the 'RdYlGn' colormap which will make visible elements green, partially hidden elements yellow, and hidden elements red.  Note that the observer is in the positive w-direction.
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Python Code:
!pip install -I "phoebe>=2.2,<2.3"
%matplotlib inline
Explanation: Wilson-Devinney Style Meshing
NOTE: Wilson-Devinney Style meshing requires developer mode in PHOEBE and is meant to be used for testing, not used for science.
Setup
Let's first make sure we have the latest version of PHOEBE 2.2 installed. (You can comment out this line if you don't use pip for your installation or don't want to update to the latest release).
End of explanation
import phoebe
from phoebe import u # units
import numpy as np
import matplotlib.pyplot as plt
phoebe.devel_on() # CURRENTLY REQUIRED FOR WD-STYLE MESHING (WHICH IS EXPERIMENTAL)
logger = phoebe.logger()
b = phoebe.default_binary()
Explanation: As always, let's do imports and initialize a logger and a new bundle.  See Building a System for more details.
End of explanation
b.set_value_all('mesh_method', 'wd')
b.set_value_all('eclipse_method', 'graham')
Explanation: Changing Meshing Options
Next we need to add compute options and change the mesh_style for all stars from 'marching' to 'wd'
End of explanation
b.add_dataset('mesh', compute_times=[0, 0.5], dataset='mesh01', columns=['visibilities'])
Explanation: Adding Datasets
Next let's add a mesh dataset so that we can plot our Wilson-Devinney style meshes
End of explanation
b.run_compute(irrad_method='none')
Explanation: Running Compute
End of explanation
afig, mplfig = b['mesh01@model'].plot(time=0.5, x='us', y='vs',
                                      show=True)
Explanation: Plotting
End of explanation
afig, mplfig = b['primary@mesh01@model'].plot(time=0.0,  x='us', y='vs',
                                              ec='blue', fc='gray', 
                                              xlim=(-0.2,0.2), ylim=(-0.2,0.2), 
                                              show=True)
Explanation: Now let's zoom in so we can see the layout of the triangles.  Note that Wilson-Devinney uses trapezoids, but since PHOEBE uses triangles, we take each of the trapezoids and split it into two triangles.
End of explanation
afig, mplfig = b['primary@mesh01@model'].plot(time=0.0, x='us', y='ws', 
                                              ec='blue', fc='gray', 
                                              xlim=(-0.1,0.1), ylim=(-2.75,-2.55), 
                                              show=True)
Explanation: And now looking down from above.  Here you can see the gaps between the surface elements (and you can also see some of the subdivision that's taking place along the limb).
End of explanation
afig, mplfig = b['secondary@mesh01@model'].plot(time=0.0, x='us', y='ws', 
                                                ec='face', fc='visibilities',
                                                show=True)
Explanation: And see which elements are visible at the current time.  This defaults to use the 'RdYlGn' colormap which will make visible elements green, partially hidden elements yellow, and hidden elements red.  Note that the observer is in the positive w-direction.
End of explanation
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