KPG1_XYD2W

Converts linear data co-ordinates to world co-ordinates

Description:

The co-efficients of the linear transformation from world co-ordinates to data co-ordinates are supplied in arguments SCALE and OFFSET. The inverse of this transformation is used to transform each supplied position from data to world co-ordinates.

Invocation

CALL KPG1_XYD2W( SCALE, OFFSET, NPOINT, XP, YP, STATUS )

Arguments

SCALE( 2 ) = DOUBLE PRECISION (Given)
The scale factors in the linear relationships between axis co-ordinates and pixel co-ordinates.
OFFSET( 2 ) = DOUBLE PRECISION (Given)
The offsets in the linear relationships between axis co-ordinates and pixel co-ordinates.
NPOINT = INTEGER (Given)
The number of points specified.
XP( NPOINT ) = REAL (Given and Returned)
Array holding the x co-ordinate of each point.
YP( NPOINT ) = REAL (Given and Returned)
Array holding the y co-ordinate of each point.
STATUS = INTEGER (Given and Returned)
The global status.

Notes:

DATA = SCALE( I ) ∗ PIXEL + OFFSET( I )

where PIXEL is a pixel co-ordinate for the I’ th dimension, and DATA is the corresponding axis co-ordinate.