cdm/src/main/java/ucar/nc2/dt/grid/GridCoordSys.java
@Override
  public int[] findXYindexFromLatLon(double lat, double lon, int[] result) {
    Projection dataProjection = getProjection();
    ProjectionPoint pp = dataProjection.latLonToProj(new LatLonPointImpl(lat, lon), new ProjectionPointImpl());

    return findXYindexFromCoord(pp.getX(), pp.getY(), result);
  }
@Override
  public int[] findXYindexFromLatLon(double lat, double lon, int[] result) {
    Projection dataProjection = getProjection();
    ProjectionPoint pp = dataProjection.latLonToProj(new LatLonPointImpl(lat, lon), new ProjectionPointImpl());

    return findXYindexFromCoord(pp.getX(), pp.getY(), result);
  }
Given a lat,lon point, find the x,y index in the coordinate system.

@param lat    latitude position.
@param lon    longitude position.
@param result put result in here, may be null
@return int[2], 0=x,1=y indices in the coordinate system of the point. These will be -1 if out of range.