g.transform1grass
Computes a coordinate transformation based on the control points.
Usage
g.transform
g.transform help
g.transform [-srx]
group=name
order=integer
[format=string
[,string, ...]]
[coords=name]
[--verbose]
[--quiet]
Keywords
general, transformation, GCP
Overview
g.transform is an utility to compute transformation based upon GCPs and output error measurements.
Notes
For coordinates given with the coords file option or fed from stdin, the input format is "x y" with one coordinate pair per line.
The transformations are:
order=1:
e = [E0 E1][1].[1]
[E2 0][e] [n]
n = [N0 N1][1].[1]
[N2 0][e] [n]
order=2:
e = [E0 E1 E3][1 ] [1 ]
[E2 E4 0][e ].[n ]
[E5 0 0][e²] [n²]
n = [N0 N1 N3][1 ] [1 ]
[N2 N4 0][e ].[n ]
[N5 0 0][e²] [n²]
order=3:
e = [E0 E1 E3 E6][1 ] [1 ]
[E2 E4 E7 0][e ].[n ]
[E5 E8 0 0][e²] [n²]
[E9 0 0 0][e³] [n³]
n = [N0 N1 N3 N6][1 ] [1 ]
[N2 N4 N7 0][e ].[n ]
[N5 N8 0 0][e²] [n²]
[N9 0 0 0][e³] [n³]
["." = dot-product, (AE).N = N'EA.]
In other words, order=1 and order=2 are equivalent to order=3 with the higher coefficients equal to zero.
Releases
4 releases since Debian 5.0 (Lenny); the text changed 3 times.