# [Scipy-tickets] [SciPy] #1412: Bug in griddata (Code does not return)

SciPy Trac scipy-tickets@scipy....
Mon Mar 21 07:06:55 CDT 2011

```#1412: Bug in griddata (Code does not return)
-------------------------------+--------------------------------------------
Reporter:  schicketanz        |       Owner:  somebody
Type:  defect             |      Status:  new
Priority:  high               |   Milestone:
Component:  scipy.interpolate  |     Version:  0.9.0
Keywords:  griddata           |
-------------------------------+--------------------------------------------
I have found a bug in griddata. The code does not return in my example. It
is difficult to reduce the data, because then the code  suddenly works. I
have no idea what to do to locate the problem further.

Here is the example code:

import numpy as np
from scipy.interpolate import griddata

#coord is a circle with an regular grid
A = np.zeros(coord.shape[0])
coordi = np.array([[ 0.02803372, -0.03142812]]) #This should return nan

#This does not work (Code does not return)
print griddata(coord, A, coordi)

#The triangulation works
from scipy.interpolate import LinearNDInterpolator
ip = LinearNDInterpolator(coord, A, fill_value=np.nan)
print 'triangulation works'

#This works!
#The point is outside the convex hull. The data near this point is defined
by index
index = (coord[:,0]>0.02) & (coord[:,0]<0.035) & (coord[:,1]>-0.04)
print griddata(coord[index,:], A[index], coordi)

#If the data is shifted or scaled the example works

--
Ticket URL: <http://projects.scipy.org/scipy/ticket/1412>
SciPy <http://www.scipy.org>
SciPy is open-source software for mathematics, science, and engineering.
```