GWCS Documentation

Getting GWCS

To install the latest release:

pip install gwcs

To install as a conda package from conda-forge:

conda install -c conda-forge gwcs

To install the latest development version from source (not generally recommendedß unless one needs a very new feature or bug fix):

pip install git+https://github.com/spacetelescope/gwcs.git

Introductions

For Users

• Using Generalized World Coordinate System Models
  • Brief Introduction and Outline
  • User Perspective
    • Terminology and Conventions
    • Simple Image Use
    • Use with Spectra
    • Simple Slit Case
    • Narrowing General Transforms
    • Modifying Transforms / Using Intermediate Frames
    • A Notes about Performance
    • Saving and Reading GWCS Objects
  • Motivations for GWCS
    • HST WCS Headaches
    • Advantages of GWCS

Constructing GWCS Models

• Introduction to Constructing Generalized World Coordinate System Models
  • Pixel Conventions and Definitions
  • Basic Structure of a GWCS Object
    • A step-by-step example of constructing an imaging GWCS object.
• Adding distortion to the imaging example
• An IFU Example - managing a discontiguous WCS
  • Using a pixel to slice mapping
  • Custom model storing transforms in a dictionary

Advanced User Topics

• Common Interface for World Coordinate System - APE 14
• Using the WCS object
  • Inspecting Available Coordinate Frames
  • Using Bounding Box
  • Manipulating Transforms
  • Inverse Transformations
• WCS User Tools
• Listing of imaging_wcs.asdf
• WCS validation
• Fitting a WCS to input pixels & sky positions
• FITS Equivalent WCS Example

Reference

• API
  • gwcs.wcs Package
    • Classes
    • Class Inheritance Diagram
  • gwcs.coordinate_frames Package
    • axes_order and conversion between objects and arguments
    • Functions
    • Classes
    • Class Inheritance Diagram
  • gwcs.wcstools Module
    • Functions
  • gwcs.selector Module
    • Classes
    • Class Inheritance Diagram
  • gwcs.spectroscopy Module
    • Classes
    • Class Inheritance Diagram
  • gwcs.geometry Module
    • Classes
    • Class Inheritance Diagram

See also

• The modeling package in astropy

• The coordinates package in astropy

• The Advanced Scientific Data Format (ASDF) standard and its Python implementation