Changeset 779 for trunk/GSASIImath.py

Timestamp:

Oct 4, 2012 4:30:34 PM (10 years ago)

Author:

vondreele

Message:

try polynomial expansion for density peak fitting - OK result

File:

• trunk/GSASIImath.py (modified) (1 diff)

trunk/GSASIImath.py

@@ -831 +831 @@
     def rhoCalc(parms,rX,rY,rZ,res,SGLaue):
         Mag,x0,y0,z0,sig = parms
-        return norm*Mag*np.exp(-((x0-rX)**2+(y0-rY)**2+(z0-rZ)**2)/(2.*sig**2))/(sig*res**3)
+        z = -((x0-rX)**2+(y0-rY)**2+(z0-rZ)**2)/(2.*sig**2)
+#        return norm*Mag*np.exp(z)/(sig*res**3)     #not slower but some faults in LS
+        return norm*Mag*(1.+z+z**2/2.)/(sig*res**3)
         
     def peakFunc(parms,rX,rY,rZ,rho,res,SGLaue):