MATLAB: Putting function values in meshgrid format

meshgrid format

I have coordinate vectors X and Y and corresponding vector of function values Z. Points (Xi,Yi) are distributed irregularly on plane. I'm trying to convert these points to a regular mesh with constant spacing, calculate corresponding values Z and plot them using surf. What is the best way to do it in matlab? I was looking at interp2, but it requires data in meshgrid format.

Thanks!

Best Answer

Your data may already be gridded. I would first plot it using stem3, for example:

figure
stem3(X, Y, Z)
grid on

If it appears that the data are regularly spaced with respect to ‘X’ and ‘Y’, then you only need to use reshape to create matrices from your vectors. If you then want to interpolate it, the griddata function may be easiest to use.

Related Solutions

MATLAB: Convert X,Y,Z column data into equally spacing grid of X,Y and corresponding Z

Let X,Y,Z be your data.

N = 500 ;
xi = lisnpace(min(X),max(X),N) ;
yi = lisnpace(min(Y),max(Y),N) ;
[Xi,Yi] = meshgrid(xi,yi) ;
Zi = griddata(X,Y,Z,Xi,Yi) ;

MATLAB: Surf plot for three independent matrices of 1×360

You have one matrix of three (1x360) row vectors. If your data are gridded, simply use the reshape function on each row vector to create appropriate matrices from them.

If your data are not gridded (random), use the griddata function (or similar functions) to create appropriate matrices for the surf plot.

One easy way to see if your data are gridded is to plkot them using the stem3 function. If they are gridded, that will be obvious.

Best Answer

Related Solutions

MATLAB: Convert X,Y,Z column data into equally spacing grid of X,Y and corresponding Z

MATLAB: Surf plot for three independent matrices of 1×360

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