<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>ICRSCoordinates — Astropy v0.2.4</title> <link rel="stylesheet" href="../_static/bootstrap-astropy.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript"> var DOCUMENTATION_OPTIONS = { URL_ROOT: '../', VERSION: '0.2.4', COLLAPSE_INDEX: false, FILE_SUFFIX: '.html', HAS_SOURCE: true }; </script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="shortcut icon" href="../_static/astropy_logo.ico"/> <link rel="top" title="Astropy v0.2.4" href="../index.html" /> <link rel="up" title="Astronomical Coordinate Systems (astropy.coordinates)" href="../coordinates/index.html" /> <link rel="next" title="IllegalHourError" href="astropy.coordinates.errors.IllegalHourError.html" /> <link rel="prev" title="HorizontalCoordinates" href="astropy.coordinates.builtin_systems.HorizontalCoordinates.html" /> </head> <body> <div class="topbar"> <a class="brand" title="Documentation Home" href="../index.html"></a> <ul> <li><a class="homelink" title="AstroPy Homepage" href="http://www.astropy.org"></a></li> <li><a title="General Index" href="../genindex.html">Index</a></li> <li><a title="Python Module Index" href="../py-modindex.html">Modules</a></li> <li> <form action="../search.html" method="get"> <input type="text" name="q" placeholder="Search" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </li> </ul> </div> <div class="related"> <h3>Navigation</h3> <ul> <li class="right"> <a href="astropy.coordinates.errors.IllegalHourError.html" title="IllegalHourError"> next » </a> </li> <li class="right"> <a href="astropy.coordinates.builtin_systems.HorizontalCoordinates.html" title="HorizontalCoordinates"> « previous </a> | </li> <li> <a href="../index.html">Astropy v0.2.4</a> » </li> <li><a href="../coordinates/index.html" accesskey="U">Astronomical Coordinate Systems (<tt class="docutils literal"><span class="pre">astropy.coordinates</span></tt>)</a> »</li> <li>ICRSCoordinates</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="icrscoordinates"> <h1>ICRSCoordinates<a class="headerlink" href="#icrscoordinates" title="Permalink to this headline">¶</a></h1> <dl class="class"> <dt id="astropy.coordinates.builtin_systems.ICRSCoordinates"> <em class="property">class </em><tt class="descclassname">astropy.coordinates.builtin_systems.</tt><tt class="descname">ICRSCoordinates</tt><big>(</big><em>*args</em>, <em>**kwargs</em><big>)</big><a class="reference external" href="http://github.com/astropy/astropy/tree/v0.2.4/astropy/coordinates/builtin_systems.py#L29" title="Push the Edit button on the next page"><span class="edit-on-github viewcode-link"> [edit on github]</span></a><a class="reference internal" href="../_modules/astropy/coordinates/builtin_systems.html#ICRSCoordinates"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#astropy.coordinates.builtin_systems.ICRSCoordinates" title="Permalink to this definition">¶</a></dt> <dd><p>Bases: <a class="reference internal" href="astropy.coordinates.coordsystems.SphericalCoordinatesBase.html#astropy.coordinates.coordsystems.SphericalCoordinatesBase" title="astropy.coordinates.coordsystems.SphericalCoordinatesBase"><tt class="xref py py-class docutils literal"><span class="pre">astropy.coordinates.coordsystems.SphericalCoordinatesBase</span></tt></a></p> <p>A coordinate in the ICRS.</p> <p>If you’re looking for “J2000” coordinates, and aren’t sure if you want to use this or <a class="reference internal" href="astropy.coordinates.builtin_systems.FK5Coordinates.html#astropy.coordinates.builtin_systems.FK5Coordinates" title="astropy.coordinates.builtin_systems.FK5Coordinates"><tt class="xref py py-obj docutils literal"><span class="pre">FK5Coordinates</span></tt></a>, you probably want to use ICRS. It’s more well-defined as a catalog coordinate and is an inertial system.</p> <table class="docutils field-list" frame="void" rules="none"> <col class="field-name" /> <col class="field-body" /> <tbody valign="top"> <tr class="field-odd field"><th class="field-name">Parameters :</th><td class="field-body"><p class="first"><strong>coordstr</strong> : str</p> <blockquote> <div><p>A single string with the coordinates. Cannot be used with <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt> and <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt> nor <tt class="xref py py-obj docutils literal"><span class="pre">x</span></tt>/<tt class="xref py py-obj docutils literal"><span class="pre">y</span></tt>/<tt class="xref py py-obj docutils literal"><span class="pre">z</span></tt>.</p> </div></blockquote> <p><strong>ra</strong> : <tt class="xref py py-obj docutils literal"><span class="pre">Angle</span></tt>, float, int, str</p> <blockquote> <div><p>This must be given with <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt>.</p> </div></blockquote> <p><strong>dec</strong> : <tt class="xref py py-obj docutils literal"><span class="pre">Angle</span></tt>, float, int, str</p> <blockquote> <div><p>This must be given with <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt>.</p> </div></blockquote> <p><strong>distance</strong> : <tt class="xref py py-obj docutils literal"><span class="pre">Distance</span></tt>, optional</p> <blockquote> <div><p>This may be given with <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt> and <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt> or <tt class="xref py py-obj docutils literal"><span class="pre">coordstr</span></tt> and not <tt class="xref py py-obj docutils literal"><span class="pre">x</span></tt>, <tt class="xref py py-obj docutils literal"><span class="pre">y</span></tt>, or <tt class="xref py py-obj docutils literal"><span class="pre">z</span></tt>. If not given, <tt class="xref py py-obj docutils literal"><span class="pre">None</span></tt> (unit sphere) will be assumed.</p> </div></blockquote> <p><strong>x</strong> : number</p> <blockquote> <div><p>The first cartesian coordinate. Must be given with <tt class="xref py py-obj docutils literal"><span class="pre">y</span></tt> and <tt class="xref py py-obj docutils literal"><span class="pre">z</span></tt> and not with <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt> or <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt> nor <tt class="xref py py-obj docutils literal"><span class="pre">coordstr</span></tt>.</p> </div></blockquote> <p><strong>y</strong> : number</p> <blockquote> <div><p>The second cartesian coordinate. Must be given with <tt class="xref py py-obj docutils literal"><span class="pre">x</span></tt> and <tt class="xref py py-obj docutils literal"><span class="pre">z</span></tt> and not with <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt> or <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt> nor <tt class="xref py py-obj docutils literal"><span class="pre">coordstr</span></tt>.</p> </div></blockquote> <p><strong>z</strong> : number</p> <blockquote> <div><p>The third cartesian coordinate. Must be given with <tt class="xref py py-obj docutils literal"><span class="pre">x</span></tt> and <tt class="xref py py-obj docutils literal"><span class="pre">y</span></tt> and not with <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt> or <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt> nor <tt class="xref py py-obj docutils literal"><span class="pre">coordstr</span></tt>.</p> </div></blockquote> <p><strong>cartpoint</strong> : <tt class="xref py py-obj docutils literal"><span class="pre">CartesianPoints</span></tt></p> <blockquote> <div><p>A cartesian point with the coordinates. Cannot be used with any other arguments.</p> </div></blockquote> <p><strong>unit</strong> :</p> <blockquote> <div><p>The <tt class="xref py py-obj docutils literal"><span class="pre">unit</span></tt> parameter’s interpretation depends on what other parameters are given:</p> <ul> <li><dl class="first docutils"> <dt>If <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt> and <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt> or <tt class="xref py py-obj docutils literal"><span class="pre">coordstr</span></tt> are given:</dt> <dd><p class="first last"><tt class="xref py py-obj docutils literal"><span class="pre">unit</span></tt> must be a length-2 sequence specifying the units of <tt class="xref py py-obj docutils literal"><span class="pre">ra</span></tt> and <tt class="xref py py-obj docutils literal"><span class="pre">dec</span></tt>, respectively. They can be either <tt class="xref py py-obj docutils literal"><span class="pre">UnitBase</span></tt> objects or strings that will be converted using <tt class="xref py py-obj docutils literal"><span class="pre">Unit</span></tt>. They can also be None to attempt to automatically interpret the units (see <a class="reference internal" href="astropy.coordinates.angles.Angle.html#astropy.coordinates.angles.Angle" title="astropy.coordinates.angles.Angle"><tt class="xref py py-obj docutils literal"><span class="pre">Angle</span></tt></a> for details.) If <tt class="xref py py-obj docutils literal"><span class="pre">unit</span></tt> is just <tt class="xref py py-obj docutils literal"><span class="pre">None</span></tt>, this will be interpreted the same as <tt class="docutils literal"><span class="pre">(None,</span> <span class="pre">None)</span></tt>.</p> </dd> </dl> </li> <li><dl class="first docutils"> <dt>If <tt class="xref py py-obj docutils literal"><span class="pre">x</span></tt>, <tt class="xref py py-obj docutils literal"><span class="pre">y</span></tt>, and <tt class="xref py py-obj docutils literal"><span class="pre">z</span></tt> are given:</dt> <dd><p class="first last"><tt class="xref py py-obj docutils literal"><span class="pre">unit</span></tt> must be a single unit with dimensions of length</p> </dd> </dl> </li> </ul> </div></blockquote> <p><strong>obstime</strong> : <tt class="xref py py-obj docutils literal"><span class="pre">Time</span></tt> or None</p> <blockquote> <div><p>The time of observation for this coordinate. If None, it will be taken to be the same as the <a class="reference internal" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.equinox" title="astropy.coordinates.builtin_systems.ICRSCoordinates.equinox"><tt class="xref py py-obj docutils literal"><span class="pre">equinox</span></tt></a>.</p> </div></blockquote> <p><strong>Alternatively, a single argument that is any kind of spherical coordinate</strong> :</p> <p><strong>can be provided, and will be converted to ICRSCoordinates and used as this</strong> :</p> <p class="last"><strong>coordinate.</strong> :</p> </td> </tr> </tbody> </table> <p class="rubric">Attributes Summary</p> <table border="1" class="longtable docutils"> <colgroup> <col width="10%" /> <col width="90%" /> </colgroup> <tbody valign="top"> <tr class="row-odd"><td><a class="reference internal" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.equinox" title="astropy.coordinates.builtin_systems.ICRSCoordinates.equinox"><tt class="xref py py-obj docutils literal"><span class="pre">equinox</span></tt></a></td> <td></td> </tr> <tr class="row-even"><td><a class="reference internal" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.latangle" title="astropy.coordinates.builtin_systems.ICRSCoordinates.latangle"><tt class="xref py py-obj docutils literal"><span class="pre">latangle</span></tt></a></td> <td></td> </tr> <tr class="row-odd"><td><a class="reference internal" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.lonangle" title="astropy.coordinates.builtin_systems.ICRSCoordinates.lonangle"><tt class="xref py py-obj docutils literal"><span class="pre">lonangle</span></tt></a></td> <td></td> </tr> <tr class="row-even"><td><a class="reference internal" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.obstime" title="astropy.coordinates.builtin_systems.ICRSCoordinates.obstime"><tt class="xref py py-obj docutils literal"><span class="pre">obstime</span></tt></a></td> <td></td> </tr> </tbody> </table> <p class="rubric">Attributes Documentation</p> <dl class="attribute"> <dt id="astropy.coordinates.builtin_systems.ICRSCoordinates.equinox"> <tt class="descname">equinox</tt><a class="reference internal" href="../_modules/astropy/coordinates/builtin_systems.html#ICRSCoordinates.equinox"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.equinox" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <dl class="attribute"> <dt id="astropy.coordinates.builtin_systems.ICRSCoordinates.latangle"> <tt class="descname">latangle</tt><a class="reference internal" href="../_modules/astropy/coordinates/builtin_systems.html#ICRSCoordinates.latangle"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.latangle" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <dl class="attribute"> <dt id="astropy.coordinates.builtin_systems.ICRSCoordinates.lonangle"> <tt class="descname">lonangle</tt><a class="reference internal" href="../_modules/astropy/coordinates/builtin_systems.html#ICRSCoordinates.lonangle"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.lonangle" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> <dl class="attribute"> <dt id="astropy.coordinates.builtin_systems.ICRSCoordinates.obstime"> <tt class="descname">obstime</tt><a class="reference internal" href="../_modules/astropy/coordinates/builtin_systems.html#ICRSCoordinates.obstime"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#astropy.coordinates.builtin_systems.ICRSCoordinates.obstime" title="Permalink to this definition">¶</a></dt> <dd></dd></dl> </dd></dl> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"><h3>Page Contents</h3> <ul> <li><a class="reference internal" href="#">ICRSCoordinates</a></li> </ul> </div> </div> <div class="clearer"></div> </div> <footer class="footer"> <p class="pull-right"> <a href="../_sources/_generated/astropy.coordinates.builtin_systems.ICRSCoordinates.txt" rel="nofollow">Page Source</a> <a href="#">Back to Top</a></p> <p> © Copyright 2011-2013, The Astropy Developers.<br/> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.1.3. 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