Scattered data interpolation is the case where your data points are randomly scattered, not on some regular lattice.
Interp3 applies to the case where your data lies on a regular lattice, in 3 dimensions for the independent variables.
Now, lets look at your data. Is it scattered? NO!!!! It lies on a nice rectangular grid, in 3 dimensions.
That the lattice is not a perfectly regular one is not important. I stored it in an array called xyzw.
altitude = permute(reshape(xyzw(:,1),[7 5 4]),[2 3 1]);
machnum = permute(reshape(xyzw(:,2),[7 5 4]),[2 3 1]);
powersetting = permute(reshape(xyzw(:,3),[7 5 4]),[2 3 1]);
fuelcons = permute(reshape(xyzw(:,4),[7 5 4]),[2 3 1]);
Now, lets try using interp3.
interp3(altitude,machnum,powersetting,fuelcons,1500,0.23,1900)
ans =
0.16129
The trick is that you needed to get those arrays in the correct order. You can see I had to be careful, using a reshape and a permute.
