<html>#2514: broken support for piecewise polytropes in IllinoisGRMHD
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<tr><td style='text-align:right'> Reporter:</td><td>Roland Haas</td></tr>
<tr><td style='text-align:right'> Status:</td><td>new</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td>development version</td></tr>
<tr><td style='text-align:right'> Type:</td><td>bug</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>minor</td></tr>
<tr><td style='text-align:right'>Component:</td><td></td></tr>
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<p>Looking at the source code IllinoisGRMHD in the ET seems to support piecewise polytropic EOS, at the very least for a single piece by setting up IllinoisGRMHD’s <code>gamma_th</code> parameter and the first entry in the <code>eos_params_arrays2</code> grid array (eg by setting ID_converter_ILGRMHD’s <code>Initial_Gamma</code> and <code>Initial_K</code> parameters). However D_converter_ILGRMHD contains an explicit check for a simple Gamma-law (ie no difference between thermal and cold Gamma) in</p>
<div class="codehilite language-c++"><pre><span></span><span class="c1">// P = (\Gamma - 1) rho epsilon</span>
<span class="c1">// -> \Gamma = P/(rho epsilon) + 1</span>
<span class="kt">double</span> <span class="n">measured_gamma</span> <span class="o">=</span> <span class="p">(</span> <span class="n">P</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">/</span><span class="p">(</span><span class="n">rho_b</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="o">*</span> <span class="n">eps</span><span class="p">[</span><span class="n">index</span><span class="p">])</span> <span class="o">+</span> <span class="mf">1.0</span> <span class="p">);</span>
<span class="k">if</span><span class="p">(</span><span class="n">rho_b</span><span class="p">[</span><span class="n">index</span><span class="p">]</span><span class="o">></span><span class="n">rho_b_atm</span> <span class="o">&&</span> <span class="n">fabs</span><span class="p">(</span><span class="n">gamma_th</span> <span class="o">-</span> <span class="n">measured_gamma</span><span class="p">)</span><span class="o">/</span><span class="n">gamma_th</span> <span class="o">></span> <span class="mf">1e-2</span><span class="p">)</span>
<span class="n">CCTK_VError</span><span class="p">(</span><span class="n">VERR_DEF_PARAMS</span><span class="p">,</span>
<span class="s">"Expected simple gamma law with gamma_th=%.15e, but found a point with gamma l
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2514/broken-support-for-piecewise-polytropes-in'>https://bitbucket.org/einsteintoolkit/tickets/issues/2514/broken-support-for-piecewise-polytropes-in</a></p>
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