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<h1>Source code for astropy.units.equivalencies</h1><div class="highlight"><pre>
<span class="c"># Licensed under a 3-clause BSD style license - see LICENSE.rst</span>
<span class="sd">"""</span>
<span class="sd">A set of standard astronomical equivalencies.</span>
<span class="sd">"""</span>
<span class="kn">from</span> <span class="nn">__future__</span> <span class="kn">import</span> <span class="p">(</span><span class="n">absolute_import</span><span class="p">,</span> <span class="n">division</span><span class="p">,</span> <span class="n">print_function</span><span class="p">,</span>
<span class="n">unicode_literals</span><span class="p">)</span>
<span class="kn">from</span> <span class="nn">..constants</span> <span class="kn">import</span> <span class="n">si</span> <span class="k">as</span> <span class="n">_si</span>
<span class="kn">from</span> <span class="nn">.</span> <span class="kn">import</span> <span class="n">si</span>
<span class="kn">from</span> <span class="nn">.</span> <span class="kn">import</span> <span class="n">cgs</span>
<span class="n">__all__</span> <span class="o">=</span> <span class="p">[</span><span class="s">'spectral'</span><span class="p">,</span> <span class="s">'spectral_density'</span><span class="p">]</span>
<div class="viewcode-block" id="spectral"><a class="viewcode-back" href="../../../_generated/astropy.units.equivalencies.spectral.html#astropy.units.equivalencies.spectral">[docs]</a><span class="k">def</span> <span class="nf">spectral</span><span class="p">():</span>
<span class="sd">"""</span>
<span class="sd"> Returns a list of equivalence pairs that handle spectral</span>
<span class="sd"> wavelength, frequency, and energy equivalences.</span>
<span class="sd"> Allows conversions between wavelength units, frequency units and</span>
<span class="sd"> energy units as they relate to light.</span>
<span class="sd"> """</span>
<span class="k">return</span> <span class="p">[</span>
<span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">m</span><span class="p">,</span> <span class="n">si</span><span class="o">.</span><span class="n">Hz</span><span class="p">,</span> <span class="k">lambda</span> <span class="n">x</span><span class="p">:</span> <span class="n">_si</span><span class="o">.</span><span class="n">c</span><span class="o">.</span><span class="n">value</span> <span class="o">/</span> <span class="n">x</span><span class="p">),</span>
<span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">m</span><span class="p">,</span> <span class="n">si</span><span class="o">.</span><span class="n">J</span><span class="p">,</span> <span class="k">lambda</span> <span class="n">x</span><span class="p">:</span> <span class="p">(</span><span class="n">_si</span><span class="o">.</span><span class="n">c</span><span class="o">.</span><span class="n">value</span> <span class="o">*</span> <span class="n">_si</span><span class="o">.</span><span class="n">h</span><span class="o">.</span><span class="n">value</span><span class="p">)</span> <span class="o">/</span> <span class="n">x</span><span class="p">),</span>
<span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">Hz</span><span class="p">,</span> <span class="n">si</span><span class="o">.</span><span class="n">J</span><span class="p">,</span> <span class="k">lambda</span> <span class="n">x</span><span class="p">:</span> <span class="n">_si</span><span class="o">.</span><span class="n">h</span><span class="o">.</span><span class="n">value</span> <span class="o">*</span> <span class="n">x</span><span class="p">)</span>
<span class="p">]</span>
</div>
<div class="viewcode-block" id="spectral_density"><a class="viewcode-back" href="../../../_generated/astropy.units.equivalencies.spectral_density.html#astropy.units.equivalencies.spectral_density">[docs]</a><span class="k">def</span> <span class="nf">spectral_density</span><span class="p">(</span><span class="n">sunit</span><span class="p">,</span> <span class="n">sfactor</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Returns a list of equivalence pairs that handle spectral density</span>
<span class="sd"> with regard to wavelength and frequency.</span>
<span class="sd"> """</span>
<span class="n">c_Aps</span> <span class="o">=</span> <span class="n">_si</span><span class="o">.</span><span class="n">c</span><span class="o">.</span><span class="n">value</span> <span class="o">*</span> <span class="mi">10</span> <span class="o">**</span> <span class="mi">10</span>
<span class="n">fla</span> <span class="o">=</span> <span class="n">cgs</span><span class="o">.</span><span class="n">erg</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">angstrom</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">cm</span> <span class="o">**</span> <span class="mi">2</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">s</span>
<span class="n">fnu</span> <span class="o">=</span> <span class="n">cgs</span><span class="o">.</span><span class="n">erg</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">Hz</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">cm</span> <span class="o">**</span> <span class="mi">2</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">s</span>
<span class="n">nufnu</span> <span class="o">=</span> <span class="n">cgs</span><span class="o">.</span><span class="n">erg</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">cm</span> <span class="o">**</span> <span class="mi">2</span> <span class="o">/</span> <span class="n">si</span><span class="o">.</span><span class="n">s</span>
<span class="n">lafla</span> <span class="o">=</span> <span class="n">nufnu</span>
<span class="k">def</span> <span class="nf">converter</span><span class="p">(</span><span class="n">x</span><span class="p">):</span>
<span class="k">return</span> <span class="n">x</span> <span class="o">*</span> <span class="p">(</span><span class="n">sunit</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">AA</span><span class="p">,</span> <span class="n">sfactor</span><span class="p">,</span> <span class="n">spectral</span><span class="p">())</span> <span class="o">**</span> <span class="mi">2</span> <span class="o">/</span> <span class="n">c_Aps</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">iconverter</span><span class="p">(</span><span class="n">x</span><span class="p">):</span>
<span class="k">return</span> <span class="n">x</span> <span class="o">/</span> <span class="p">(</span><span class="n">sunit</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">AA</span><span class="p">,</span> <span class="n">sfactor</span><span class="p">,</span> <span class="n">spectral</span><span class="p">())</span> <span class="o">**</span> <span class="mi">2</span> <span class="o">/</span> <span class="n">c_Aps</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">converter_fnu_nufnu</span><span class="p">(</span><span class="n">x</span><span class="p">):</span>
<span class="k">return</span> <span class="n">x</span> <span class="o">*</span> <span class="n">sunit</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">Hz</span><span class="p">,</span> <span class="n">sfactor</span><span class="p">,</span> <span class="n">spectral</span><span class="p">())</span>
<span class="k">def</span> <span class="nf">iconverter_fnu_nufnu</span><span class="p">(</span><span class="n">x</span><span class="p">):</span>
<span class="k">return</span> <span class="n">x</span> <span class="o">/</span> <span class="n">sunit</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">Hz</span><span class="p">,</span> <span class="n">sfactor</span><span class="p">,</span> <span class="n">spectral</span><span class="p">())</span>
<span class="k">def</span> <span class="nf">converter_fla_lafla</span><span class="p">(</span><span class="n">x</span><span class="p">):</span>
<span class="k">return</span> <span class="n">x</span> <span class="o">*</span> <span class="n">sunit</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">AA</span><span class="p">,</span> <span class="n">sfactor</span><span class="p">,</span> <span class="n">spectral</span><span class="p">())</span>
<span class="k">def</span> <span class="nf">iconverter_fla_lafla</span><span class="p">(</span><span class="n">x</span><span class="p">):</span>
<span class="k">return</span> <span class="n">x</span> <span class="o">/</span> <span class="n">sunit</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">AA</span><span class="p">,</span> <span class="n">sfactor</span><span class="p">,</span> <span class="n">spectral</span><span class="p">())</span>
<span class="k">return</span> <span class="p">[</span>
<span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">AA</span><span class="p">,</span> <span class="n">fnu</span><span class="p">,</span> <span class="n">converter</span><span class="p">,</span> <span class="n">iconverter</span><span class="p">),</span>
<span class="p">(</span><span class="n">fla</span><span class="p">,</span> <span class="n">fnu</span><span class="p">,</span> <span class="n">converter</span><span class="p">,</span> <span class="n">iconverter</span><span class="p">),</span>
<span class="p">(</span><span class="n">si</span><span class="o">.</span><span class="n">AA</span><span class="p">,</span> <span class="n">si</span><span class="o">.</span><span class="n">Hz</span><span class="p">,</span> <span class="n">converter</span><span class="p">,</span> <span class="n">iconverter</span><span class="p">),</span>
<span class="p">(</span><span class="n">fla</span><span class="p">,</span> <span class="n">si</span><span class="o">.</span><span class="n">Hz</span><span class="p">,</span> <span class="n">converter</span><span class="p">,</span> <span class="n">iconverter</span><span class="p">),</span>
<span class="p">(</span><span class="n">fnu</span><span class="p">,</span> <span class="n">nufnu</span><span class="p">,</span> <span class="n">converter_fnu_nufnu</span><span class="p">,</span> <span class="n">iconverter_fnu_nufnu</span><span class="p">),</span>
<span class="p">(</span><span class="n">fla</span><span class="p">,</span> <span class="n">lafla</span><span class="p">,</span> <span class="n">converter_fla_lafla</span><span class="p">,</span> <span class="n">iconverter_fla_lafla</span><span class="p">),</span>
<span class="p">]</span></div>
</pre></div>
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