<?xml version="1.0" encoding="utf-8"?><feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en"><generator uri="https://jekyllrb.com/" version="4.4.1">Jekyll</generator><link href="https://santiagocasas.github.io/feed.xml" rel="self" type="application/atom+xml"/><link href="https://santiagocasas.github.io/" rel="alternate" type="text/html" hreflang="en"/><updated>2026-04-20T16:45:18+00:00</updated><id>https://santiagocasas.github.io/feed.xml</id><title type="html">Santiago Casas</title><subtitle>Personal and academic website of Dr. rer. nat. Santiago Casas. Theoretical Physicist, Cosmologist, Astrophysicist. PhD Heidelberg University 2017. </subtitle><entry><title type="html">Montepython issues</title><link href="https://santiagocasas.github.io/blog/2024/montepython-notes/" rel="alternate" type="text/html" title="Montepython issues"/><published>2024-08-25T12:57:00+00:00</published><updated>2024-08-25T12:57:00+00:00</updated><id>https://santiagocasas.github.io/blog/2024/montepython-notes</id><content type="html" xml:base="https://santiagocasas.github.io/blog/2024/montepython-notes/"><![CDATA[<h1 id="gcspectro-likelihood">GCspectro likelihood</h1> <p>Run technicalities in [[MontePython Oneloop Runs]]</p> <ol> <li>Installation issues: <ol> <li>Class Oneloop C-code not compatible with older <code class="language-plaintext highlighter-rouge">gcc 9.4</code>, it is compatible with <code class="language-plaintext highlighter-rouge">gcc~&gt;11.0</code></li> <li>Classy does not work with <code class="language-plaintext highlighter-rouge">numpy &gt;=2.0</code> .</li> <li>Montepython requires <code class="language-plaintext highlighter-rouge">numpy&gt;1.23.5</code> because of a <code class="language-plaintext highlighter-rouge">scipy.optimize import fsolve</code></li> </ol> </li> <li>w0, wa priors are not important in (Analytical Marginalized) AM likelihoods.</li> <li>w0, wa priors are important in full likelihoods, getting constantly errors like:</li> </ol> <div class="language-plaintext highlighter-rouge"><div class="highlight"><pre class="highlight"><code>desinomarg.err:48:Error in Class: perturbations_init(L:796) :condition (w_fld_ini &gt;= 0.) is true; The fluid is meant to be negligible at early time, and unimportant for defining the initial conditions of other species. You are using parameters for which this assumption may break down, since at early times you have w_fld(a---&gt;0) = 1.406016e-03 &gt;= 0
</code></pre></div></div> <ol> <li>AM likelihoods do not generate their own fiducials, one has to generate them using the full likelihoods and be very careful with fiducial parameters.</li> <li>MP likelihoods when reaching max number of Nsteps, finish (on the cluster at least) with <code class="language-plaintext highlighter-rouge">FAILED, ExitCode 137</code> giving the wrong impression that the run has failed or there was a problem. They should exit with <code class="language-plaintext highlighter-rouge">ExitCode 0</code></li> <li>When generating the fiducial, the MP likelihood returns :</li> </ol> <div class="language-plaintext highlighter-rouge"><div class="highlight"><pre class="highlight"><code>256             warnings.warn(
257                 "Writing fiducial model in %s, for %s likelihood\n" % (
258                     self.fid_filename, self.name))
259             return 1j

</code></pre></div></div> <p>This is a strange complex number return, because in the case of using the option <code class="language-plaintext highlighter-rouge">--display-each-chi2</code> at the same time as <code class="language-plaintext highlighter-rouge">-f0</code> to generate the fiducial, this return value gets added to the other chi2 of other likelihoods and one gets the wrong impression that something is going on. The logic here should be clarified.</p> <ol> <li>The public (Casas et al 2023) ISTF-like <code class="language-plaintext highlighter-rouge">euclid_spectroscopic</code> likelihood does not work for <code class="language-plaintext highlighter-rouge">m_nu=0</code> because it automatically requests <code class="language-plaintext highlighter-rouge">P_cb</code>, <code class="language-plaintext highlighter-rouge">f_cb</code> and other <code class="language-plaintext highlighter-rouge">cb</code> quantities, which are not available in this case from class.</li> <li>The oneloop spectroscopic likelihoods do not contain <code class="language-plaintext highlighter-rouge">P_cb</code> explicitly, working with <code class="language-plaintext highlighter-rouge">P_mm</code> only.</li> <li>The runs of the MP validation paper were done in the <code class="language-plaintext highlighter-rouge">Omega_m, sigma8</code> and <strong>camb</strong> basis. The oneloop runs have been done using the <strong>class</strong> basis and <code class="language-plaintext highlighter-rouge">logAs</code> making a comparison more difficult.</li> </ol>]]></content><author><name></name></author><category term="sample-posts"/><category term="cosmology"/><summary type="html"><![CDATA[Montepython problems]]></summary></entry><entry><title type="html">Simple cosmicfishpie example</title><link href="https://santiagocasas.github.io/blog/2023/jupyter-notebook/" rel="alternate" type="text/html" title="Simple cosmicfishpie example"/><published>2023-11-11T12:57:00+00:00</published><updated>2023-11-11T12:57:00+00:00</updated><id>https://santiagocasas.github.io/blog/2023/jupyter-notebook</id><content type="html" xml:base="https://santiagocasas.github.io/blog/2023/jupyter-notebook/"><![CDATA[<div class="jupyter-notebook" style="position: relative; width: 100%; margin: 0 auto;"> <div class="jupyter-notebook-iframe-container"> <iframe src="/assets/jupyter/Cosmology-Calculator.ipynb.html" style="position: absolute; top: 0; left: 0; border-style: none;" width="100%" height="100%" onload="this.parentElement.style.paddingBottom = (this.contentWindow.document.documentElement.scrollHeight + 10) + 'px'"></iframe> </div> </div> <p>Note that the jupyter notebook supports both light and dark themes.</p>]]></content><author><name></name></author><category term="cosmology"/><category term="formatting"/><category term="jupyter"/><summary type="html"><![CDATA[A cosmology calculator from CosmicFishPie]]></summary></entry></feed>