NRAO Home > CASA > CASA Toolkit Reference Manual
coordsys.convertdirection - Function

1.1.3 Convert the direction coordinate to the specified frame by rotating as necessary about the reference pixel so the axes line up with the cardinal directions.


Description

Convert the direction coordinate in the coordinate system to the specified frame by rotating about the reference pixel so that the resulting coordinate axes are parallel to the cardinal directions. The resulting coordinate will not have a conversion layer, even if the input direction coordinate does. A conversion layer can be set after by running cs.setconversiontype(). Be aware that if you attach the resulting coordinate system to an image whose pixels have not been rotated around the reference pixel in the same manner, you will likely get an image for which the pixels do not match up to world coordinate values. This method should only be used by experienced users who know what they are doing. It was written originally to facilitate rotating the direction coordinate since the implementation of imregrid requires this in certain circumstances. The conversion is done in place; a new coordinate system tool is not created. The returned record represents an angular quantity through which the old direction coordinate was rotated to create the new coordinate.

Arguments





Inputs

frame

Reference frame to convert to.

allowed:

string

Default:

Returns
record

Example

 
 

__________________________________________________________________


More information about CASA may be found at the CASA web page

Copyright © 2016 Associated Universities Inc., Washington, D.C.

This code is available under the terms of the GNU General Public Lincense


Home | Contact Us | Directories | Site Map | Help | Privacy Policy | Search