Copyright (c) 2004 Gordon D. Carrie. All rights reserved.

Licensed under the Open Software License version 2.1

Please address questions and feedback to user0@tkgeomap.org

@(#) $Id: tclgeomap_procs.n,v 1.9 2007/06/22 22:40:49 tkgeomap Exp $

tclgeomap_procs, latitude, longitude, latlon, circle, fillsegment, grid_list, ocean_list - supplementary procedures for tclgeomap. 2

package require tclgeomap_procs ?2?
geomap::latitude geoPt
geomap::longitude geoPt
geomap::latlon geoPt
geomap::prt_time time year month day hour minute second
geomap::circle center radius {unit gsdeg}
geomap::fillsegment p1 p2 {d 2.0}
geomap::grid_list {s 15.0}
geomap::ocean_list {s 15.0}
geomap::projections
geomap::proj_info proj_name

The tclgeomap package provides procedures to use with the tclgeomap.

geomap::latitude geoPt This convenience procedure returns the latitude member of geoPt, which should be a list of form {lat lon}.

geomap::longitude geoPt This convenience procedure returns the longitude member of geoPt, which should be a list of form {lat lon}.

geomap::latlon geoPt This procedure returns the geographic point corresponding to geoPt. If geoPt is a {latitude longitude} value, the procedure merely returns it. If geoPt is a location given in degrees, minutes, seconds format, it returns the corresponding decimal representation. Otherwise the procedure raises an error.

geomap::prt_time time year month day hour minute second This procedures takes time value time, which should be a list of form {year month day hour minute second} and puts the elements into variables named year month day hour minute second.

geomap::circle center radius {unit gsdeg} This procedure returns a list of geographic points that define a circle about geographic point center with radius radius. Optional unit unit should be a unit value known to the geoplace step command.

geomap::fillsegment p1 p2 {d 2.0} This procedure returns a list of geographic points on the great circle connecting geographic points p1 and p2 that are not further than d great circle degrees apart. This can be useful for defining long segments that will assume the correct shape in various map projections.

geomap::grid_list {s 15.0} This procedure returns a list of grid lines that cover the Earth. The returned list is in a format intelligible to the geolinearray fmlist ... command. Spacing s gives the rectangle size in degrees.

geomap::ocean_list {s 15.0} This procedure returns a list of closed rectangles that cover the Earth. The returned list is in a format intelligible to the geolinearray fmlist ... command. The outlines can be useful for initializing the globe with a solid color (like blue) and then drawing land features on top. Spacing s gives the rectangle size in degrees.

geomap::projections Returns a list of known projections.

geomap::proj_info proj_name Returns a list of form {reference domain}, where reference is the type of reference projection proj_name uses, either point or longitude, and domain is how much of the Earth projection proj_name transforms, either globe or hemisphere.

These procedures are part of the tclgeomap_procs package, which is defined in file tclgeomap_procs.tcl of the tkgeomap installation. Gordon Carrie <user0@tkgeomap.org>