How to perform regridding (1.0d to 0.5d) using bilinear interpolation for an irregular area? I need to regrid temperature dataset from 1 degree to 0.5 degree. In case we have data available for all grids falling in a square, as shown below, we can simply regrid it using bilinear/bicubic interpolation method in MATLAB.



But, the data grids which I have forms an irregular shape i.e., there are no values outsie the given grids as shown below.



How to do regriding in this case ?
Try something like this:

[x_grid,y_grid] = meshgrid(1:100,1:100);
z_grid=griddata(x_data,y_data,z_data,x_grid(:),y_grid(:),'v4');


You can change the method of interpolation if you prefer something else.

See:
http://www.mathworks.com/help/matlab/ref/griddata.html