Subroutine: IRCO_TRANSFORM
Purpose: Transform between coordinate systems
Category WORLD COORDINATES, IRAS
File: irco.shl
Author: Do Kester
Person resp.: Do Kester
Address: guspace!do or rugfx4!do (uucp)
Use: call irco_transform(
xyz1, I double precision array(3,n)
coor1, I integer
xyz2, O double precision array(3,n)
coor2, I integer
n ) I integer
xyz1 vectors to be transformed
coor1 coordinate system in which XYZ1 are given
coor2 desired coordinate system
n number of vectors to be transformed
xyz2 vectors in system coor2
Description:
The vectors in XYZ1 and XYZ2 are three-dimensional unit vectors.
The vectors XYZ1 which are in coordinate system COOR1 are
transformed into vectors XYZ2 in coordinate system COOR2 by
multiplication with a transformation matrix. The matrix is
either given in advance (COORn <= 5), or it has to be (re)defined
using the routines IRCO_NEWCOOR, IRCO_PRECESS or IRCO_PLATE.
It is allowed that XYZ1 and XYZ2 are the same array.
It is not essential that XYZ1 are unit vectors; they will
retain their length upon transformation.
Externals:
Updates: 850624 Albrecht de Jonge, original code
900424 DK, documentation and rewrite