Dear Vitaliy,
Thank you for your reply.
i tried your suggested solution but unfortunately it didn't work in my case...
I am attaching a part of my data here, the format is {Theta,Phi,f}
indata= {
{0.000Pi, 0.000Pi, 0.600},
{0.000Pi, 0.033Pi, 0.320},
{0.500Pi, 0.033Pi, 0.405},
{1.000Pi, 0.033Pi, 0.328},
{1.500Pi, 0.033Pi, 0.406},
{0.150Pi, 0.144Pi, 0.093},
{0.350Pi, 0.144Pi, 0.115},
{0.650Pi, 0.144Pi, 0.095},
{0.850Pi, 0.144Pi, 0.151},
{1.150Pi, 0.144Pi, 0.150},
{1.350Pi, 0.144Pi, 0.102},
{1.650Pi, 0.144Pi, 0.115},
{1.850Pi, 0.144Pi, 0.084},
{0.000Pi, 0.206Pi, 1.541},
{0.050Pi, 0.206Pi, 1.165},
{0.450Pi, 0.206Pi, -1.403},
{0.500Pi, 0.206Pi, -1.505},
{0.550Pi, 0.206Pi, -1.449},
{1.450Pi, 0.206Pi, -1.415},
{1.500Pi, 0.206Pi, -1.468},
{1.950Pi, 0.206Pi, 1.153},
{0.189Pi, 0.256Pi, -1.197},
{0.311Pi, 0.256Pi, -0.757}
}
As you can see the internal step i am using isn't necessarily regular since i am generating the data outside of mathematica.
for interpolation:
f = Interpolation;
i get the following error: "The coordinates do not lie on a structured tensor product grid"
and for:
f = Interpolation;
it just doesn't do anything..
I wonder if the data structure is the reason? If so, I'm sorry i didn't make it perfectly clear.
Is there a way to get around it?
Thank you again for your help.
Dan (Bai DaLei)