Merge pull request GeostatsGuy#7 from sharkman424/myBranch

finished docstring for backtr function

Author: jessepisel

geostatspy/geostats.py

@@ -36,7 +36,8 @@ def backtr(df,vcol,vr,vrg,zmin,zmax,ltail,ltpar,utail,utpar):
     :param ltpar: lower tail extrapolation parameter
     :param utail: upper tail value
     :param utpar: upper tail extrapolation parameter
-    :return: TODO
+    :return: backtr: the DataFrame column, which has been back transformed using
+             the provided transformation table and tail extrapolation.
     """    
 
     EPSLON=1.0e-20