KPG1_PXSCL

Determines pixel scales at a given grid position

Description:

This routine determines the scales of the WCS axes in the current Frame of the supplied FrameSet. For a specified WCS axis, the returned scale is the WCS axis increment produced by moving a distance of one grid pixel away from the supplied " AT" position, along the WCS axis.

Invocation

CALL KPG1_PXSCL( IWCS, AT, PXSCL, STATUS )

Arguments

IWCS = INTEGER (Given)
The FrameSet.
AT( ∗ ) = DOUBLE PRECISION (Given)
The position in GRID co-ordinates at which the pixel scales are to be determined. Note, the pixel scales may vary across the data array if the WCS Mappings are non-linear. The array should have one element for each GRID axis.
PXSCL( ∗ ) = DOUBLE PRECISION (Returned)
The returned pixel scales. Note, the pixel scale for both celestial longitude and latitude axes are returned as an arc-distance in radians. The array should have one element for each WCS axis.
STATUS = INTEGER (Given and Returned)
The global status.