Cubic spline interpolation in 3D

First of all thank you very much for your interesting website.
I have a question that I hope you can help me. I have some points contain x,y and z parameter. I want to calculate z number if I have x and y. I already do this in Matlab. here is some part of my code in Matlab.

mydata=[0.12 6 600
0.13 5.5 600
0.165 5 600
0.18 4 600
0.2 3.25 600
0.22 3 600
0.23 2.25 600
0.18 13.5 900
0.215 13 900
0.26 12 900
0.29 10 900
0.33 8.5 900
0.35 7 900
0.38 5 900
0.4 4 900
0.22 19 1105
0.27 18 1105
0.305 16.5 1105
0.34 15 1105
0.39 12 1105
0.425 10 1105
0.45 7.75 1105
0.235 23 1200
0.29 21 1200
0.34 19 1200
0.375 17 1200
0.42 14 1200
0.45 12 1200
0.48 8.5 1200
0.5 7 1200
0.28 32 1400
0.335 30 1400
0.4 28 1400
0.45 24 1400
0.5 20 1400
0.54 16 1400
0.575 13 1400
0.605 9.5 1400];
x=mydata(:,1);
y=mydata(:,2);
z=mydata(:,3);
ft = ‘cubicinterp’;
% Fit model to data.
caldata= fit( [xData, yData], zData, ft, ‘Normalize’, ‘on’ );

I wonder if you can help me , how can I do it in C# using math.net.