Re: number of grid points, GRIBs and MapProjectionDisplay

• To: Stuart Maclean <stuart@xxxxxxxxxxxxxxxxxx>
• Subject: Re: number of grid points, GRIBs and MapProjectionDisplay
• From: Tom Whittaker <tomw@xxxxxxxxxxxxx>
• Date: Fri, 01 Apr 2005 08:33:10 -0600

Hi Stuart:

Nx - Number of points along x-axis
Ny - Number of points along y-axis

=========================
public Rectangle2D.Double(double x, double y, double w, double h)

Parameters:
    w - the width of the newly constructed Rectangle2D
    h - the height of the newly constructed Rectangle2D
=========================

Thus Nx and Ny are used for the "width" and "height" of the Rectangle2D.
Hope this clarifies things for you.

Best wishes,

tom


Stuart Maclean wrote:

Something is puzzling me re the visad.jmet.GRIBCoordinateSystem and the
MapProjectionDisplay example for display side coord systems...


Do Ni and Nj, in constructor params in the GRIB class, represent the
number of grid _points_ or the number of grid point _intervals_ ?? It
suggests the number of grid points, given the comments in the source code.

But if this is true, and it is the number of points and not intervals,
then would the range, and hence the defaultMapArea(), be 1,1,Ni,Nj and not
0,0,Ni,Nj?

Otherwise the MapProjectionDisplay's adapter class, which maps lat/lons to
the display range -1 to 1, will be mapping row 0 to -1 and row Ni to 1.
Using this logic, the axis accommodates Ni + 1 grid points?

I'm sure there's an easy explanation, I just can't find it ;)

stuart

--
Tom Whittaker (tomw@xxxxxxxxxxxxx)
University of Wisconsin-Madison
Space Science and Engineering Center
Cooperative Institute for Meteorological Satellite Studies
Phone/VoiceMail: 608.262.2759

• References:
  • number of grid points, GRIBs and MapProjectionDisplay
    • From: Stuart Maclean