adding the basic feko read function

pyuvdata/uvbeam/feko_beam.py

@@ -0,0 +1,28 @@
+import numpy as np
+import glob
+
+def read_feko(file_name_prefix,freq_p,theta_p,phi_p):
+    """
+    Reads in a typical feko output file and returns numpy arrays of the power beam and efield beams.
+    """
+    beam_square = np.zeros((freq_p,theta_p,phi_p))
+    etheta_square90 = np.zeros((freq_p,theta_p,phi_p),dtype = 'complex')
+    ephi_square90 = np.zeros((freq_p,theta_p,phi_p),dtype = 'complex')
+
+    f1 = open(file_name_prefix)
+
+
+    z = theta_p*phi_p +10# ---> change this to no.of theta * no.of phi + No.of header lines
+    c=0
+    for line in f1:
+        if c%z ==0:
+            co=0
+        if c % z >= 10: 
+            x = list(map(float,line.split()))
+            beam_square[int(c/z), co%181,int(co/181)] = 10**(x[8]/10)##*** beam_square [freq,theta,phi]***
+            etheta_square90[int(c/z), co%181,int(co/181)] = x[2] + 1j*(x[3])
+            ephi_square90[int(c/z), co%181,int(co/181)] = x[4] + 1j*x[5]
+            co = co+1
+        c = c+1
+
+    return beam_square, etheta_square90, ephi_square90