3input vs 1 output Interpolation Problem

Hello !

I have a set of data attached (Data.xlsx), there are 3 input vectors and 1 output vector, output vector named 'Error', Input vectors named X,Y,Z. based on this ,I would like to make an interpolation table so that I can use it for other intermidiate input values to get output.

please help to find a way how can I use interpolation in Matlab for 3 inputs and one output ?

Answer 1

[Ameer Hamza]

You need to use scatteredInterpolant()

data = readtable('Data.xlsx');
idx = find(isnan(data.X), 1);
data(idx:end, :) = [];

mdl = scatteredInterpolant(data.X, data.Y, data.Z, data.Error);

err_val = mdl(245, 1500, 50) % interpolate at x = 245, y = 1500, z = 50

[Abyay Ray]

Thanks a lot ...its working...

Answer 2

[Walter Roberson]

t = rmmissing(readtable('Data.xlsx'));
x=t.X; y=t.Y; z=t.Z; err=t.Error;
F = scatteredInterpolant(x,y,z,err);

%now F(x,y,z) gives you the interpolation. 

%to visualize:
[X,Y,Z] = meshgrid(linspace(min(x),max(x),50),linspace(min(y),max(y),50),linspace(min(z),max(z),50));
E = F(X,Y,Z);
v = -50:12.5:25;
for V = v; isosurface(X,Y,Z,E,V); end
colorbar

You have some obvious discontinuities for Error == 0, especially near x == 75; you might want to look at those values more closely. Be sure to rotate the plot as some of the graphs are odd.

[Abyay Ray]

Thanks a lot...