Fix normalization factor for m != 0

Author: AnkitBarik

magField.py

@@ -4,7 +4,7 @@
 from planetmagfields.libbfield import *
 import sys
 
-levels=30
+levels=20
 cmap='RdBu_r'
 proj = 'Mollweide'
 r = 1

planetmagfields/libgauss.py

@@ -183,6 +183,10 @@ def getB(lmax,glm,hlm,idx,r,p2D,th2D,planet="earth"):
                 fac_m = 1.
             else:
                 fac_m = (-1)**m
+
+            if m != 0:
+                fac_m *= np.sqrt(2)
+
             fac = fac_m * (l+1) * r**(-l-2) * np.sqrt((4.*np.pi)/(2*l+1))
 
             G = glm[idx[l,m]] * np.real(ylm)