Chris Beaumont's IDL Library

Download source code

single page | use frames     summary     class     fields     routine details     file attributes



xyzadv, head, x, y, z, a, d, v [, ortho=ortho]

This procedure is an extenion of (and a wrapper for) the xyad program in the astronomy user's library. It converts (x,y,z) pixel coordinates to (a,d,v) sky / velocity coordinates for a 3D data cube, based on the fits header.

This procedure calls extast3 from the Beaumont IDL library and xyad from the IDL Astronomy User's Library.


head in required

A fits header. String array

x in required

x pixel coordinates. scalar or vector

y in required

y pixel coordinates. scalar or vector

z in required

z pixel coordinates. scalar or vector



ortho in optional

Set this keyword if the third axis of the input coordinates is orthogonal to the first two; that is, if xyz describe a cube, and x and y are the same for each slice. When this is true, the computation can be performed more quickly.

Author information


March 2010: Written by Chris Beaumont May 2010: Fixed a bug in the call to xy2ad. cnb. June 2011: Optimized for case when x,y,z describe a cube, with (x,y) constant along z slices.

File attributes

Modifcation date: Tue Jun 7 11:00:02 2011
Lines: 68