Index: /issm/trunk-jpl/src/m/interp/interp.py
===================================================================
--- /issm/trunk-jpl/src/m/interp/interp.py	(revision 17654)
+++ /issm/trunk-jpl/src/m/interp/interp.py	(revision 17655)
@@ -2,4 +2,9 @@
 import numpy as npy
 from scipy.interpolate import CloughTocher2DInterpolator, Rbf
+try:
+	import matplotlib.pyplot as plt
+except ImportError:
+	print 'could not import matplotlib, no plotting functions enabled.\
+			Set plotonly=False in function call'
 
 def MeshSplineToMesh2d(x,y,data,xi,yi,tol=1e-6,**kwargs):#{{{
@@ -66,5 +71,5 @@
 	return interpdata
 #}}}
-def GridSplineToMesh2d(x,y,data,xi,yi,default_value=npy.nan):#{{{
+def GridSplineToMesh2d(x,y,data,xi,yi,default_value=npy.nan,plotonly=False):#{{{
 	'''
 	python analog to InterpFromGridToMesh.  This routine uses
@@ -84,7 +89,9 @@
 	default_value:	default value if points lie outside the convex hull of input
 						points (defaults to nan if not specified)
+	plotonly:		plot the data to be interpolated using imshow (useful for
+						identifying holes in data and problems with interpolation)
 
 	Usage:
-		interpdata=GridToMesh(x,y,data,xi,yi,default_value=npy.nan)
+		interpdata=GridToMesh(x,y,data,xi,yi,default_value=npy.nan,plotonly=False)
 
 	Examples:
@@ -115,4 +122,9 @@
 	flatsubdata=subdata.ravel()
 
+	if plotonly:
+		plt.imshow(npy.flipud(subdata),origin='upper')
+		plt.show()
+		return
+
 	# mask out any nan's in the data and corresponding coordinate points
 	mask=npy.isnan(flatsubdata)