visad/src/main/java/ucar/nc2/iosp/grid/GridHorizCoordSys.java
private void makeMercator() {
    /**
     * Construct a Mercator Projection.
     * @param lon0 longitude of origin (degrees)
     * @param par standard parallel (degrees). cylinder cuts earth at this latitude.
     */
    double Latin = gds.getDouble(GridDefRecord.LAD);
    // name depends on Grib version 1 or 2
    if (Double.isNaN(Latin))
      Latin = gds.getDouble(GridDefRecord.LATIN);
    double Lo1 = gds.getDouble(GridDefRecord.LO1); //gds.Lo1;
    double La1 = gds.getDouble(GridDefRecord.LA1); //gds.La1;

    // put longitude origin at first point - doesnt actually matter
    proj = new Mercator(Lo1, Latin);

    // find out where
    ProjectionPoint startP = proj.latLonToProj(
        new LatLonPointImpl(La1, Lo1));
    startx = startP.getX();
    starty = startP.getY();

    if (Double.isNaN(getDxInKm())) {
      setDxDy(startx, starty, proj);
    }

    attributes.add(new Attribute(GridCF.GRID_MAPPING_NAME, "mercator"));
    attributes.add(new Attribute(GridCF.STANDARD_PARALLEL, Latin));
    attributes.add(new Attribute(GridCF.LONGITUDE_OF_PROJECTION_ORIGIN, Lo1));

    if (GridServiceProvider.debugProj) {
      double Lo2 = gds.getDouble(GridDefRecord.LO2);
      if (Lo2 < Lo1) Lo2 += 360;
      double La2 = gds.getDouble(GridDefRecord.LA2);
      LatLonPointImpl endLL = new LatLonPointImpl(La2, Lo2);
      System.out.println("GridHorizCoordSys.makeMercator: end at latlon= " +
          endLL);

      ProjectionPointImpl endPP = (ProjectionPointImpl) proj.latLonToProj(endLL);
      System.out.println("   start at proj coord " +
          new ProjectionPointImpl(startx, starty));
      System.out.println("   end at proj coord " + endPP);

      double endx = startx + (getNx() - 1) * getDxInKm();
      double endy = starty + (getNy() - 1) * getDyInKm();
      System.out.println("   should be x=" + endx + " y=" + endy);
    }
  }
private void makeMercator() {
    /**
     * Construct a Mercator Projection.
     * @param lon0 longitude of origin (degrees)
     * @param par standard parallel (degrees). cylinder cuts earth at this latitude.
     */
    double Latin = gds.getDouble(GridDefRecord.LAD);
    // name depends on Grib version 1 or 2
    if (Double.isNaN(Latin))
      Latin = gds.getDouble(GridDefRecord.LATIN);
    double Lo1 = gds.getDouble(GridDefRecord.LO1); //gds.Lo1;
    double La1 = gds.getDouble(GridDefRecord.LA1); //gds.La1;

    // put longitude origin at first point - doesnt actually matter
    proj = new Mercator(Lo1, Latin);

    // find out where
    ProjectionPoint startP = proj.latLonToProj(
        new LatLonPointImpl(La1, Lo1));
    startx = startP.getX();
    starty = startP.getY();

    if (Double.isNaN(getDxInKm())) {
      setDxDy(startx, starty, proj);
    }

    attributes.add(new Attribute(GridCF.GRID_MAPPING_NAME, "mercator"));
    attributes.add(new Attribute(GridCF.STANDARD_PARALLEL, Latin));
    attributes.add(new Attribute(GridCF.LONGITUDE_OF_PROJECTION_ORIGIN, Lo1));

    if (GridServiceProvider.debugProj) {
      double Lo2 = gds.getDouble(GridDefRecord.LO2);
      if (Lo2 < Lo1) Lo2 += 360;
      double La2 = gds.getDouble(GridDefRecord.LA2);
      LatLonPointImpl endLL = new LatLonPointImpl(La2, Lo2);
      System.out.println("GridHorizCoordSys.makeMercator: end at latlon= " +
          endLL);

      ProjectionPointImpl endPP = (ProjectionPointImpl) proj.latLonToProj(endLL);
      System.out.println("   start at proj coord " +
          new ProjectionPointImpl(startx, starty));
      System.out.println("   end at proj coord " + endPP);

      double endx = startx + (getNx() - 1) * getDxInKm();
      double endy = starty + (getNy() - 1) * getDyInKm();
      System.out.println("   should be x=" + endx + " y=" + endy);
    }
  }
Make a Mercator projection