d.set.viewproj

NAME

d.set.viewproj- Sets the current view projection.
(GRASS Viewproj Display Program)

SYNOPSIS

d.set.viewproj
d.set.viewproj help
d.set.viewproj proj=projection

DESCRIPTION

d.set.viewproj sets the current view projection (proj=projection). See d.auto.viewproj if you are unfamiliar with PROJ.

The projections are based upon PROJ (originally from the USGS). More information about PROJ is available at PROJ.4- Cartographic Projections Library

Viewproj programs work only with lat-lon data.

Parameters:

proj=projection: Name of a PROJ projection.

There are over twenty additional PROJ parameters which may be entered.
See the PROJ manual or Projections Transform List (PROJ4) for the projections and their parameters.

Each PROJ parameter is entered without a plus sign. Each PROJ flag must have "=y" appended to the flag and be entered without a plus sign. For example, the PROJ command line

proj +proj=utm +south +zone=2

becomes

d.set.viewproj proj=utm south=y zone=2

If the user does not use any arguments, the program will prompt the user to enter them. Consult the PROJ manual to determine the projections and the appropriate parameters for each projection.

NOTES

If the projection parameters are not accepted by PROJ, the current view projection will not be changed and the program will exit with an error message, as in the following example.

d.set.viewproj proj=abc
PROJ doesn't accept these parameters!

Warning: Some versions of PROJ use different elliptical parameters. For example, ellps=wgs84 versus ellps=WGS84.

The user must set the region (with g.region) appropriately for the view projection. If the region is not set correctly, the drawing programs (d.grid.viewproj, d.rast.viewproj, and d.vect.viewproj) will exit with an error message, as in the following example.

Mercator maps are restricted to the region between 85N and 85S. If n=90 and e=180, the following error message will occur when attempting to draw:
ERROR: latlon_to_cartPROJ cannot map 180.000000,90.000000 in cart_PROJ

AUTHORS