Added capability for blue earth option in plot routine

plot.py

@@ -2,37 +2,47 @@
 
 import matplotlib.pyplot as plt
 
-# Try to match font used in document in which plot will be embedded.
-# If you plan on presenting on screen and including in a paper, you may want
-# to have two versions of the plot with different font sizes. Complicating matters
-# is the fact that some journals use sans serif for web and serif in PDFs. 
-# See also
-#   https://stackoverflow.com/questions/8753835/how-to-get-a-list-of-all-the-fonts-currently-available-for-matplotlib
-plt.rcParams.update({'font.size': 14, 'font.family': 'serif'})
+def myplots( colorEarth=False ):
+    # Try to match font used in document in which plot will be embedded.
+    # If you plan on presenting on screen and including in a paper, you may want
+    # to have two versions of the plot with different font sizes. Complicating matters
+    # is the fact that some journals use sans serif for web and serif in PDFs. 
+    # See also
+    #   https://stackoverflow.com/questions/8753835/how-to-get-a-list-of-all-the-fonts-currently-available-for-matplotlib
+    plt.rcParams.update({'font.size': 14, 'font.family': 'serif'})
+
+    fname = 'data/lines.npy'
+    print(f'Reading {fname}')
+    lines = np.load(fname)
+    print(f'Read {fname}')
+
+    # Here I've colored everything black because I don't think additional colors
+    # will add more clarity.
+    plt.plot(lines[0,:,:], lines[1,:,:], 'k')
+    plt.plot(lines[0,0,:], lines[1,0,:], 'k.')
 
-fname = 'data/lines.npy'
-print(f'Reading {fname}')
-lines = np.load(fname)
-print(f'Read {fname}')
+    # CHG: Added option to allow colored earth
+    if colorEarth:
+        earth = plt.Circle((0, 0), 1, color='b')
+    else:
+        earth = plt.Circle((0, 0), 1, color='k')
 
-# Here I've colored everything black because I don't think additional colors
-# will add more clarity.
-plt.plot(lines[0,:,:], lines[1,:,:], 'k')
-plt.plot(lines[0,0,:], lines[1,0,:], 'k.')
-earth = plt.Circle((0, 0), 1, color='k')
-plt.gca().add_patch(earth)
-plt.xlabel('y or L')
-plt.ylabel('z', rotation=0) # If label is short, I rotate to make easier to read.
-plt.axis('equal') # So the field lines are not distorted by non-unity aspect ratio.
-plt.title('Field lines for a dipole')
-plt.grid()
+    plt.gca().add_patch(earth)
+    plt.xlabel('y or L')
+    plt.ylabel('z', rotation=0) # If label is short, I rotate to make easier to read.
+    plt.axis('equal') # So the field lines are not distorted by non-unity aspect ratio.
+    plt.title('Field lines for a dipole')
+    plt.grid()
+
+    # Save PNG for copy/paste into PPT. Save SVG for viewing in browser. Save PDF
+    # Also if plot will be put into a LaTeX document.
+    plt.savefig('figures/field_lines.png', dpi=300)
+    plt.savefig('figures/field_lines.svg')
+    #plt.savefig('figures/field_lines.pdf')
+    print('Wrote figures/field_lines.{png,svg}')
+    #print('Wrote figures/field_lines.{png,svg}')
+
+    plt.show() # Needed if this script is executed from the command line.
 
-# Save PNG for copy/paste into PPT. Save SVG for viewing in browser. Save PDF
-# Also if plot will be put into a LaTeX document.
-plt.savefig('figures/field_lines.png', dpi=300)
-plt.savefig('figures/field_lines.svg')
-#plt.savefig('figures/field_lines.pdf')
-print('Wrote figures/field_lines.{png,svg}')
-#print('Wrote figures/field_lines.{png,svg}')
-
-plt.show() # Needed if this script is executed from the command line.
+if __name__ == "__main__":
+    myplots( colorEarth=True )