Grid Transformation to a new grid

Grid Transformation to a new grid

Post by capmail79- » Wed, 13 Feb 2008 19:49:19

Hello Everybody!

I want to transpose 3D Radar values from an irregular grid to a
definable 3D grid. Since I could not find any function for the 3D
problem I tried the function trigrid for 2D grids, which works very
well for the middle area of my domain, but does only poorly replicate
the radar echoes on the edges. I assume, this is due to the
interpolation of the values, which happens within the function.

If I could have the source code of the function trigrid, i could
possibly adapt it to my problem, but i could not find that.

So I tried to find a function which just takes the value of the
nearest neighbour and writes it on the new grid, without any
interpolation. I did not succeed here, too.

Does anybody know a program for my problem or where I can get the
source code of the function trigrid? Or even better, it would be
great, if there is a program which could handle the grid
transformation problem quickly and efficiently on a 3D grid!

Thanks, very much!


Grid Transformation to a new grid

Post by davi » Wed, 13 Feb 2008 20:23:49

I use this one to interpol with nearest_neighbour:


Is this what you want?



Grid Transformation to a new grid

Post by Spon » Wed, 13 Feb 2008 20:37:50

Take a look at the QHULL and QGRID3 functions, particularly Example 3
in the QGRID3 help file. Seems to me this might give you what you

All the best,