<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Mark,<div class=""><br class=""></div><div class="">I said I would send a reference to literature that discusses using sophisticated matrix inversion routines rather than something rudimentary like Gauss-Jordan elimination.   Today we discussed using LU decomposition, and at some point we should look into Singular Value Decomposition.   So far, it looks like LU decomposition solves our problem with the kinfitter.   My main source is the old “Numerical Recipes" book by Press, Flannery, Teukolsky and Vetterling.  I have the Fortran version, and a good place to start reading is page 515.</div><div class=""><br class=""></div><div class="">Cheers,</div><div class="">Reinhard<br class=""><div apple-content-edited="true" class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">_____________________________________________________________<br class="">Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.<br class="">Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.<br class="">phone: 412-268-5177           web: <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__www-2Dmeg.phys.cmu.edu_-7Eschumach&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=PMWTlI59xRjvhqYG-RheUf-M5mw5DBJNWCjXkVT2NA4&e=" class="">www-meg.phys.cmu.edu/~schumach</a><br class="">_____________________________________________________________<br class=""></div></div></div></div></div></div></div></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
</div>
<br class=""><div><blockquote type="cite" class=""><div class="">On Oct 29, 2018, at 3:01 PM, Mark Ito <<a href="mailto:marki@jlab.org" class="">marki@jlab.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">

  
  <div text="#000000" bgcolor="#FFFFFF" class=""><p class="">Please find the meeting page <a moz-do-not-send="true" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Software_Meeting,_October_30,_2018" class="">here</a>
      and below.</p><p class="">__________________________</p><div class="">
    <br class="webkit-block-placeholder"></div>
    <div id="globalWrapper" class="">
      <div id="column-content" class="">
        <div id="content" class="mw-body" role="main">
          <h2 id="firstHeading" class="firstHeading" lang="en"><span dir="auto" class="">GlueX Offline Software Meeting, October 30,
              2018</span></h2>
          <div id="bodyContent" class="mw-body-content">
            <div id="mw-content-text" dir="ltr" class="mw-content-ltr" lang="en"><p class="">GlueX Offline Software Meeting<br class="">
                Tuesday, October 30, 2018<br class="">
                3:00 pm EDT<br class="">
                JLab: CEBAF Center A110<br class="">
                BlueJeans: <a rel="nofollow" class="external text" href="https://urldefense.proofpoint.com/v2/url?u=http-3A__www.bluejeans.com_968592007&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=EcNj9N_R3ua0WpW8_BKp4AJ6ZOrBFxZlUvdUKpAA2CU&e=">968 592 007</a>
              </p>
              <h2 class=""><span class="mw-headline" id="Agenda">Agenda</span></h2>
              <ol class="">
                <li class=""> Announcements
                  <ol class="">
                    <li class=""> <a rel="nofollow" class="external text" href="https://mailman.jlab.org/pipermail/halld-offline/2018-October/003403.html">New
                        release of halld_sim: version 3.6.0</a></li>
                    <li class=""> <a rel="nofollow" class="external text" href="https://mailman.jlab.org/pipermail/halld-offline/2018-October/003405.html">New
                        bug-fix release: halld_sim 3.1.1</a></li>
                  </ol>
                </li>
                <li class=""> Review of <a href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Software_Meeting,_October_16,_2018#Minutes" title="GlueX Offline Software Meeting, October 16,
                    2018" class="">minutes from the October 16 meeting</a> (all)</li>
                <li class=""> <a rel="nofollow" class="external text" href="https://mailman.jlab.org/pipermail/halld/2018-October/000645.html">Monitoring
                    launch ver 18 @ NERSC</a> (David)</li>
                <li class=""> Events lost due to vertex fit for Lambda (Hao)</li>
                <li class=""> CCDB versions and SQLite file management (all)</li>
                <li class=""> Review of <a rel="nofollow" class="external text" href="https://halldweb.jlab.org/wiki-private/index.php/2018_Work_Packages">Offline
                    Work Packages</a> </li>
                <li class=""> Review of recent issues and pull requests:
                  <ol class="">
                    <li class=""> halld_recon
                      <ul class="">
                        <li class=""> <a rel="nofollow" class="external text" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_JeffersonLab_halld-5Frecon_issues-3Futf8-3D-25E2-259C-2593-26q-3Dis-253Aissue&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=w_2K1hzb6Je0OukHpy112IqombhUUOZPux1SlQituF0&e=">Issues</a></li>
                        <li class=""> <a rel="nofollow" class="external text" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_JeffersonLab_halld-5Frecon_pulls-3Fq-3Dis-253Apr&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=NFlD06wCnvfg2mu0G_huk68vz-nQLvyjmlP4lxhKUQc&e=">pull
                            requests</a></li>
                      </ul>
                    </li>
                    <li class=""> halld_sim
                      <ul class="">
                        <li class=""> <a rel="nofollow" class="external text" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_JeffersonLab_halld-5Fsim_issues-3Futf8-3D-25E2-259C-2593-26q-3Dis-253Aissue&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=5XDJKQeja9OCUbIc1Hu-nw2V8Wc9RdIh0ZhFwxL04SM&e=">Issues</a></li>
                        <li class=""> <a rel="nofollow" class="external text" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_JeffersonLab_halld-5Fsim_pulls-3Fq-3Dis-253Apr&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=9f4kbvDLwrUXgr5VsCNBRLgRCEJ5wR-ga8lDgW-VvLs&e=">pull
                            requests</a></li>
                      </ul>
                    </li>
                  </ol>
                </li>
                <li class=""> Review of <a rel="nofollow" class="external text" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__groups.google.com_forum_-23-2521forum_gluex-2Dsoftware&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=MyrtgxkAZVSJp_YVa0uI9G_2TRcYVT_hmjQhrVmH05c&e=">recent
                    discussion on the GlueX Software Help List</a> (all)</li>
                <li class=""> Action Item Review (all)</li>
              </ol>
              <h2 class=""><span class="mw-headline" id="Communication_Information">Communication
                  Information</span></h2>
              <h3 class=""><span class="mw-headline" id="Remote_Connection">Remote
                  Connection</span></h3>
              <ul class="">
                <li class=""> The BlueJeans meeting number is 968 592 007 .</li>
                <li class=""> <a rel="nofollow" class="external text" href="https://urldefense.proofpoint.com/v2/url?u=http-3A__bluejeans.com_968592007&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=oyKV5joTkJsuRYv6hh48IMTw3i-IrYD-ZUAHHU0DdAY&m=-SXQWFu24QYu6q-an81l3I726nKxTZry9jCsm_J_5y4&s=Zr1ys3VVP-gKGvGwuoZvGP_0ttGZTNoVXiJoc00wOgM&e=">Join the
                    Meeting</a> via BlueJeans</li>
              </ul>
              <h3 class=""><span class="mw-headline" id="Slides">Slides</span></h3><p class="">Talks can be deposited in the directory <code class="">/group/halld/www/halldweb/html/talks/2018</code>
                on the JLab CUE. This directory is accessible from the
                web at <a rel="nofollow" class="external free" href="https://halldweb.jlab.org/talks/2018/">https://halldweb.jlab.org/talks/2018/</a>
                .
              </p>
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          <li id="lastmod" class=""> This page was last modified on 29 October
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    <pre class="moz-signature" cols="72">-- 
Mark Ito, <a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org">marki@jlab.org</a>, (757)269-5295
</pre>
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