Problems using interp1 in GUI

hello,

i want to use the interp1 function in a callback function of my GUI. But it seems that interp1 does not get the inputvariables. I have set them global but there is still an error:

Interpolation requires at least two sample points in each dimension.

the code works well outside of the callback function.

[Geoff Hayes]

Sebastian - please post some of your code (i.e. that from your callback) to indicate how you are using the global variables with respect to the interp1 function