<html>#2417: include PN expressions for initial momenta for BBH simualtion
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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>open</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td></td></tr>
<tr><td style='text-align:right'> Type:</td><td>proposal</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>major</td></tr>
<tr><td style='text-align:right'>Component:</td><td></td></tr>
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<p>Comment (by Roland Haas):</p>
<p>I looked a bit into what needs to be present. At least for my OSX+Homebrew test system I needed:</p>
<ul>
<li>brew install jupyter</li>
<li>pip3 install sympy</li>
<li><code>sys.path.append(“/User/jenkins/Library/Python/3.8/lib/python/site-packages“)</code> otherwise it would not find the package in jupyter notebooks (but would find in python scripts, very odd)</li>
<li>no other Python package seems required</li>
</ul>
<p>Python3.8 produced 2 syntax warnings of type ‘SyntaxWarning: "is" with a literatl. Did you mean "=="?’ in mpmath, one of them line 892. Probably not much that can be done about this though.</p>
<p>The example notebook explicitly provides digits for the Euler-gamma constant. However sympy provides this as a symbol already <code>sympy.S.EuerlGamma</code> which probably could (and should) be used instead in the PN expressions (and <code>Float(sympy.S.EuerlGamma)</code> does give the correct digits).</p>
<p>None of the Python functions seem to have a Python docstring, making eg <code>help(pt.f_p_t)</code> not very useful.</p>
<p><code>NRPyPN_shortcuts.py</code> is really used as some sort of include file injection a number of symbols (among them <code>chi1U</code> etc.) into the main namespace via <code>from NRPyPN_shortcuts import *</code> which is somewhat confusing.</p>
<p>The <code>pt</code> module seems to have some internal state that is manipulated via things like <code>pt.f_p_t</code>. It would seem cleaner if instead there was a <code>pt</code> object that one created instead.</p>
<p></p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2417/include-pn-expressions-for-initial-momenta'>https://bitbucket.org/einsteintoolkit/tickets/issues/2417/include-pn-expressions-for-initial-momenta</a></p>
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