Re: [Geotools-gt2-users] Building a coverage from an array of doubles/floats?

[Ian T. <ijt...@gm...>]

On Tue, Dec 21, 2010 at 8:49 PM, Michael Bedward
<mic...@gm...> wrote:
> There was some discussion of a WritableGridCoverage2D class a while
> ago between Simone, myself and other list members. It got as far as a
> (very) basic example in the demo module
> (org.geotools.demo.coverage.WritableGridDemo). That would be the place
> for setxXXX( world-coords ) methods with interpolation options.
>
> Since your source data are already on a regular grid perhaps
> interpolation isn't required (?). If that's the case, you can simplify
> the world to grid (image) coords calculations somewhat...
>
> GridEnvelope2D gridEnv = new GridEnvelope2D(0, 0, gridWidth, gridHeight);
> ReferencedEnvelope worldEnv = new ReferencedEnvelope(minWorldX,
> maxWorldX, minWorldY, maxWorldY, crs);
> GridGeometry2D gg = new GridGeometry2D(gridEnv, worldEnv);
>
> Now you can convert from world coordinates to grid coordinates:
>
> DirectPosition2D pos = new DirectPosition2D(x, y);
> GridCoordinates2D gridCoords = gg.worldToGrid(pos);
>
> Or if your source coords are in a different projection...
>
> pos = new DirectPosition2D(srcCRS, x, y);
> GridCoordinates2D gridCoords = gg.worldToGrid(pos);
>

That is cool - I'll experiment today. I had been wondering if
GridCoordinates did anything useful for me but I couldn't work it out.

Thanks

Ian