working on DC problem CC and N

SimPEG/EM/Analytics/DC.py

@@ -0,0 +1,34 @@
+import numpy as np
+from scipy.constants import mu_0, pi
+
+def DCAnalytic(txloc, rxlocs, sigma, flag="wholespace"):
+    """
+        Analytic solution for electric potential from a postive pole
+
+        Input variables:
+
+            txloc =  a xyz location of A (+) electrode (np.r_[xa, ya, za])
+
+            rxlocs = [M, N]
+                M: xyz locations of M (+) electrode (np.c_[xmlocs, ymlocs, zmlocs])
+                N: xyz locations of N (-) electrode (np.c_[xnlocs, ynlocs, znlocs])
+
+            sigma = conductivity (either float or complex)
+            flag = "wholsespace" or "halfspace"
+
+    """
+    M = rxlocs[0]
+    N = rxlocs[1]
+
+    rM = np.sqrt( (M[:,0]-txloc[0])**2 + (M[:,1]-txloc[1])**2 + (M[:,2]-txloc[1])**2 )
+    rN = np.sqrt( (N[:,0]-txloc[0])**2 + (N[:,1]-txloc[1])**2 + (N[:,2]-txloc[1])**2 )
+
+    phiM = 1./(4*np.pi*rM*sigma)
+    phiN = 1./(4*np.pi*rN*sigma)
+    phi = phiM - phiN
+
+    if flag == "halfspace":
+        phi *= 2
+
+    return phi
+

SimPEG/EM/Analytics/__init__.py

@@ -1,3 +1,4 @@
 from TDEM import hzAnalyticDipoleT
 from FDEM import hzAnalyticDipoleF
 from FDEMcasing import *
+from DC import DCAnalytic