man v.transform () - Transforms an vector map layer from one coordinate system into another coordinate system.

NAME

v.transform - Transforms an vector map layer from one coordinate system into another coordinate system.

SYNOPSIS

v.transform

v.transform help

v.transform [-qts] input=string output=string [pointsfile=string] [xshift=float] [yshift=float] [zshift=float] [xscale=float] [yscale=float] [zscale=float] [zrot=float]

Flags:

"-q
suppress display of residuals or other information
"-t
shift all z values to bottom=0
"-s
Instead of points use transformation options (xshift, yshift, zshif, xscale, yscale, zscale, zrot)

Parameters:

"input=string
vector map to be transformed
"output=string
resultant vector map
"pointsfile=string
file holding transform coordinates
"xshift=float
shifting value for x coordinates Default: 0.0
"yshift=float
shifting value for y coordinates Default: 0.0
"zshift=float
shifting value for z coordinates Default: 0.0
"xscale=float
scaling factor for x coordinates Default: 1.0
"yscale=float
scaling factor for y coordinates Default: 1.0
"zscale=float
scaling factor for z coordinates Default: 1.0
"zrot=float
rotation around z axis in degrees counterclockwise Default: 0.0

DESCRIPTION

v.transform transforms a vector map layer from one coordinate system into another coordinate system.

NOTES

When using an ASCII table containing source and target coordinate pairs, in each row four coordinate values separated by white space have to be specified. Comments are permitted and have to be indicated by a '#' character.

Example for a points file of a linear transformation from XY to UTM coordinates (L: left, R: right, U: upper, L: lower, N, S, W, E):

# Linear transformation from XY to UTM coordinates:

# 4 maps corners defined

# UL NW

# UR NE

# LR SW

# LL SE

-584 585 598000 4920770

580 585 598020 4920770

580 -600 598020 4920750

-584 -600 598000 4920750

The ground control points may be also (ir)regularly distributed and can be more than four points.

EXAMPLE

Most DXF/DWG drawings are done within XY coordinates. To transform them to a national grid, we can use 'v.transform' with a 4 point transformation

v.transform -t in=watertowerXY out=watertowerUTM points= wt.points zscale=0.04 zshift=1320

SEE ALSO

v.in.ogr

AUTHOR

Radim Blazek, ITC-Irst, Trento, Italy

Last changed: $Date: 2005/02/03 10:59:51 $

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