MATLAB: Reduce Matrix size with interpolated data arrays

image processinginterpolation

Hi,

I have a 360*720 precipitation matrix with values in milimeter, and i desire a 180*360 matrix with interpolated data to compare my precipitation with other 180*360 data.

here you can see the original 360*720 plot of my data. please help me on this.

Thank you.

Best Answer

hello

simply use a 2D interpolation with the appropriate new Xq and Yq vectors

interp2 2-D interpolation (table lookup).

Vq = interp2(X,Y,V,Xq,Yq) interpolates to find Vq, the values of the

underlying 2-D function V at the query points in matrices Xq and Yq.

Matrices X and Y specify the points at which the data V is given.

Related Solutions

MATLAB: Determine the Z value of a 3D region for a given set of co-ordinates

the function interp2() will work. The example in the help/documentation is

[X,Y,V] = peaks(10); [Xq,Yq] = meshgrid(-3:.1:3,-3:.1:3);
        Vq = interp2(X,Y,V,Xq,Yq); mesh(Xq,Yq,Vq)

As you can see in the interp2 function it has the original X,Y,Z (or in this case V) and then the user defines the Xq and Yq points that are not on the original grid. the Xq and Yq can be a single XY pair to get the interpolated Z value.

MATLAB: Help me in using “interp2”

your input grid, X, Y, must be cuboid.

Leave your inputs the same, but change the command from interp2 to griddata (with the same arguments).

Also you will want to add 'edgecolor','none' to the surf() call.

griddata() is going to tell you that duplicate values have been averaged. I suspect -pi and +pi map to the same point with pol2cart. If you were to linspace() with 31 points and then delete the last then the overlap should disappear.

Best Answer

Related Solutions

MATLAB: Determine the Z value of a 3D region for a given set of co-ordinates

MATLAB: Help me in using “interp2”

Related Question