next up previous 264
Next: Circle - A circular or spherical region within a Frame
Up: AST Class Descriptions
Previous: Box - A box region with sides parallel to the axes of a Frame


Channel - Basic (textual) I/O channel

Description:
The Channel class implements low-level input/output for the AST library. Writing an Object to a Channel will generate a textual representation of that Object, and reading from a Channel will create a new Object from its textual representation.

Normally, when you use a Channel, you should provide "source" and "sink" functions which connect it to an external data store by reading and writing the resulting text. By default, however, a Channel will read from standard input and write to standard output.

Constructor Function:
astChannel
Inheritance
The Channel class inherits from the Object class.
Attributes
In addition to those attributes common to all Objects, every Channel also has the following attributes:

  • Comment: Include textual comments in output?

  • Full: Set level of output detail

  • Indent: Indentation increment between objects

  • ReportLevel: Selects the level of error reporting

  • Skip: Skip irrelevant data?

  • Strict: Generate errors instead of warnings?
Functions
In addition to those functions applicable to all Objects, the following functions may also be applied to all Channels:



next up previous 264
Next: Circle - A circular or spherical region within a Frame
Up: AST Class Descriptions
Previous: Box - A box region with sides parallel to the axes of a Frame

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council