<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta charset="utf-8" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="generator" content="pandoc" />


<meta name="author" content="Lei Sun" />

<meta name="date" content="2017-05-07" />

<title>Improvement on Implementation with Rmosek: Primal and Dual</title>

<script src="site_libs/jquery-1.11.3/jquery.min.js"></script>
<meta name="viewport" content="width=device-width, initial-scale=1" />
<link href="site_libs/bootstrap-3.3.5/css/readable.min.css" rel="stylesheet" />
<script src="site_libs/bootstrap-3.3.5/js/bootstrap.min.js"></script>
<script src="site_libs/bootstrap-3.3.5/shim/html5shiv.min.js"></script>
<script src="site_libs/bootstrap-3.3.5/shim/respond.min.js"></script>
<script src="site_libs/jqueryui-1.11.4/jquery-ui.min.js"></script>
<link href="site_libs/tocify-1.9.1/jquery.tocify.css" rel="stylesheet" />
<script src="site_libs/tocify-1.9.1/jquery.tocify.js"></script>
<script src="site_libs/navigation-1.1/tabsets.js"></script>
<link href="site_libs/highlightjs-9.12.0/textmate.css" rel="stylesheet" />
<script src="site_libs/highlightjs-9.12.0/highlight.js"></script>
<link href="site_libs/font-awesome-4.5.0/css/font-awesome.min.css" rel="stylesheet" />

<style type="text/css">code{white-space: pre;}</style>
<style type="text/css">
  pre:not([class]) {
    background-color: white;
  }
</style>
<script type="text/javascript">
if (window.hljs) {
  hljs.configure({languages: []});
  hljs.initHighlightingOnLoad();
  if (document.readyState && document.readyState === "complete") {
    window.setTimeout(function() { hljs.initHighlighting(); }, 0);
  }
}
</script>



<style type="text/css">
h1 {
  font-size: 34px;
}
h1.title {
  font-size: 38px;
}
h2 {
  font-size: 30px;
}
h3 {
  font-size: 24px;
}
h4 {
  font-size: 18px;
}
h5 {
  font-size: 16px;
}
h6 {
  font-size: 12px;
}
.table th:not([align]) {
  text-align: left;
}
</style>


</head>

<body>

<style type = "text/css">
.main-container {
  max-width: 940px;
  margin-left: auto;
  margin-right: auto;
}
code {
  color: inherit;
  background-color: rgba(0, 0, 0, 0.04);
}
img {
  max-width:100%;
  height: auto;
}
.tabbed-pane {
  padding-top: 12px;
}
button.code-folding-btn:focus {
  outline: none;
}
</style>


<style type="text/css">
/* padding for bootstrap navbar */
body {
  padding-top: 51px;
  padding-bottom: 40px;
}
/* offset scroll position for anchor links (for fixed navbar)  */
.section h1 {
  padding-top: 56px;
  margin-top: -56px;
}

.section h2 {
  padding-top: 56px;
  margin-top: -56px;
}
.section h3 {
  padding-top: 56px;
  margin-top: -56px;
}
.section h4 {
  padding-top: 56px;
  margin-top: -56px;
}
.section h5 {
  padding-top: 56px;
  margin-top: -56px;
}
.section h6 {
  padding-top: 56px;
  margin-top: -56px;
}
</style>

<script>
// manage active state of menu based on current page
$(document).ready(function () {
  // active menu anchor
  href = window.location.pathname
  href = href.substr(href.lastIndexOf('/') + 1)
  if (href === "")
    href = "index.html";
  var menuAnchor = $('a[href="' + href + '"]');

  // mark it active
  menuAnchor.parent().addClass('active');

  // if it's got a parent navbar menu mark it active as well
  menuAnchor.closest('li.dropdown').addClass('active');
});
</script>


<div class="container-fluid main-container">

<!-- tabsets -->
<script>
$(document).ready(function () {
  window.buildTabsets("TOC");
});
</script>

<!-- code folding -->




<script>
$(document).ready(function ()  {

    // move toc-ignore selectors from section div to header
    $('div.section.toc-ignore')
        .removeClass('toc-ignore')
        .children('h1,h2,h3,h4,h5').addClass('toc-ignore');

    // establish options
    var options = {
      selectors: "h1,h2,h3",
      theme: "bootstrap3",
      context: '.toc-content',
      hashGenerator: function (text) {
        return text.replace(/[.\\/?&!#<>]/g, '').replace(/\s/g, '_').toLowerCase();
      },
      ignoreSelector: ".toc-ignore",
      scrollTo: 0
    };
    options.showAndHide = true;
    options.smoothScroll = true;

    // tocify
    var toc = $("#TOC").tocify(options).data("toc-tocify");
});
</script>

<style type="text/css">

#TOC {
  margin: 25px 0px 20px 0px;
}
@media (max-width: 768px) {
#TOC {
  position: relative;
  width: 100%;
}
}


.toc-content {
  padding-left: 30px;
  padding-right: 40px;
}

div.main-container {
  max-width: 1200px;
}

div.tocify {
  width: 20%;
  max-width: 260px;
  max-height: 85%;
}

@media (min-width: 768px) and (max-width: 991px) {
  div.tocify {
    width: 25%;
  }
}

@media (max-width: 767px) {
  div.tocify {
    width: 100%;
    max-width: none;
  }
}

.tocify ul, .tocify li {
  line-height: 20px;
}

.tocify-subheader .tocify-item {
  font-size: 0.90em;
  padding-left: 25px;
  text-indent: 0;
}

.tocify .list-group-item {
  border-radius: 0px;
}


</style>

<!-- setup 3col/9col grid for toc_float and main content  -->
<div class="row-fluid">
<div class="col-xs-12 col-sm-4 col-md-3">
<div id="TOC" class="tocify">
</div>
</div>

<div class="toc-content col-xs-12 col-sm-8 col-md-9">




<div class="navbar navbar-default  navbar-fixed-top" role="navigation">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar">
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="index.html">truncash</a>
    </div>
    <div id="navbar" class="navbar-collapse collapse">
      <ul class="nav navbar-nav">
        <li>
  <a href="about.html">About</a>
</li>
<li>
  <a href="license.html">License</a>
</li>
      </ul>
      <ul class="nav navbar-nav navbar-right">
        <li>
  <a href="https://github.com/LSun/truncash">
    <span class="fa fa-github"></span>
     
  </a>
</li>
      </ul>
    </div><!--/.nav-collapse -->
  </div><!--/.container -->
</div><!--/.navbar -->

<!-- Add a small amount of space between sections. -->
<style type="text/css">
div.section {
  padding-top: 12px;
}
</style>

<div class="fluid-row" id="header">



<h1 class="title toc-ignore">Improvement on Implementation with <code>Rmosek</code>: Primal and Dual</h1>
<h4 class="author"><em>Lei Sun</em></h4>
<h4 class="date"><em>2017-05-07</em></h4>

</div>


<p><strong>Last updated:</strong> 2018-05-15</p>
<strong>workflowr checks:</strong> <small>(Click a bullet for more information)</small>
<ul>
<li>
<details>
<p><summary> <strong style="color:blue;">✔</strong> <strong>R Markdown file:</strong> up-to-date </summary></p>
<p>Great! Since the R Markdown file has been committed to the Git repository, you know the exact version of the code that produced these results.</p>
</details>
</li>
<li>
<details>
<p><summary> <strong style="color:blue;">✔</strong> <strong>Environment:</strong> empty </summary></p>
<p>Great job! The global environment was empty. Objects defined in the global environment can affect the analysis in your R Markdown file in unknown ways. For reproduciblity it’s best to always run the code in an empty environment.</p>
</details>
</li>
<li>
<details>
<p><summary> <strong style="color:blue;">✔</strong> <strong>Seed:</strong> <code>set.seed(12345)</code> </summary></p>
<p>The command <code>set.seed(12345)</code> was run prior to running the code in the R Markdown file. Setting a seed ensures that any results that rely on randomness, e.g. subsampling or permutations, are reproducible.</p>
</details>
</li>
<li>
<details>
<p><summary> <strong style="color:blue;">✔</strong> <strong>Session information:</strong> recorded </summary></p>
<p>Great job! Recording the operating system, R version, and package versions is critical for reproducibility.</p>
</details>
</li>
<li>
<details>
<p><summary> <strong style="color:blue;">✔</strong> <strong>Repository version:</strong> <a href="https://github.com/LSun/truncash/tree/388e65e06000e313c170a82f3ed57346f6024897" target="_blank">388e65e</a> </summary></p>
Great! You are using Git for version control. Tracking code development and connecting the code version to the results is critical for reproducibility. The version displayed above was the version of the Git repository at the time these results were generated. <br><br> Note that you need to be careful to ensure that all relevant files for the analysis have been committed to Git prior to generating the results (you can use <code>wflow_publish</code> or <code>wflow_git_commit</code>). workflowr only checks the R Markdown file, but you know if there are other scripts or data files that it depends on. Below is the status of the Git repository when the results were generated:
<pre><code>
Ignored files:
    Ignored:    .DS_Store
    Ignored:    .Rhistory
    Ignored:    .Rproj.user/
    Ignored:    analysis/.DS_Store
    Ignored:    analysis/BH_robustness_cache/
    Ignored:    analysis/FDR_Null_cache/
    Ignored:    analysis/FDR_null_betahat_cache/
    Ignored:    analysis/Rmosek_cache/
    Ignored:    analysis/StepDown_cache/
    Ignored:    analysis/alternative2_cache/
    Ignored:    analysis/alternative_cache/
    Ignored:    analysis/ash_gd_cache/
    Ignored:    analysis/average_cor_gtex_2_cache/
    Ignored:    analysis/average_cor_gtex_cache/
    Ignored:    analysis/brca_cache/
    Ignored:    analysis/cash_deconv_cache/
    Ignored:    analysis/cash_fdr_1_cache/
    Ignored:    analysis/cash_fdr_2_cache/
    Ignored:    analysis/cash_fdr_3_cache/
    Ignored:    analysis/cash_fdr_4_cache/
    Ignored:    analysis/cash_fdr_5_cache/
    Ignored:    analysis/cash_fdr_6_cache/
    Ignored:    analysis/cash_plots_cache/
    Ignored:    analysis/cash_sim_1_cache/
    Ignored:    analysis/cash_sim_2_cache/
    Ignored:    analysis/cash_sim_3_cache/
    Ignored:    analysis/cash_sim_4_cache/
    Ignored:    analysis/cash_sim_5_cache/
    Ignored:    analysis/cash_sim_6_cache/
    Ignored:    analysis/cash_sim_7_cache/
    Ignored:    analysis/correlated_z_2_cache/
    Ignored:    analysis/correlated_z_3_cache/
    Ignored:    analysis/correlated_z_cache/
    Ignored:    analysis/create_null_cache/
    Ignored:    analysis/cutoff_null_cache/
    Ignored:    analysis/design_matrix_2_cache/
    Ignored:    analysis/design_matrix_cache/
    Ignored:    analysis/diagnostic_ash_cache/
    Ignored:    analysis/diagnostic_correlated_z_2_cache/
    Ignored:    analysis/diagnostic_correlated_z_3_cache/
    Ignored:    analysis/diagnostic_correlated_z_cache/
    Ignored:    analysis/diagnostic_plot_2_cache/
    Ignored:    analysis/diagnostic_plot_cache/
    Ignored:    analysis/efron_leukemia_cache/
    Ignored:    analysis/fitting_normal_cache/
    Ignored:    analysis/gaussian_derivatives_2_cache/
    Ignored:    analysis/gaussian_derivatives_3_cache/
    Ignored:    analysis/gaussian_derivatives_4_cache/
    Ignored:    analysis/gaussian_derivatives_5_cache/
    Ignored:    analysis/gaussian_derivatives_cache/
    Ignored:    analysis/gd-ash_cache/
    Ignored:    analysis/gd_delta_cache/
    Ignored:    analysis/gd_lik_2_cache/
    Ignored:    analysis/gd_lik_cache/
    Ignored:    analysis/gd_w_cache/
    Ignored:    analysis/knockoff_10_cache/
    Ignored:    analysis/knockoff_2_cache/
    Ignored:    analysis/knockoff_3_cache/
    Ignored:    analysis/knockoff_4_cache/
    Ignored:    analysis/knockoff_5_cache/
    Ignored:    analysis/knockoff_6_cache/
    Ignored:    analysis/knockoff_7_cache/
    Ignored:    analysis/knockoff_8_cache/
    Ignored:    analysis/knockoff_9_cache/
    Ignored:    analysis/knockoff_cache/
    Ignored:    analysis/knockoff_var_cache/
    Ignored:    analysis/marginal_z_alternative_cache/
    Ignored:    analysis/marginal_z_cache/
    Ignored:    analysis/mosek_reg_2_cache/
    Ignored:    analysis/mosek_reg_4_cache/
    Ignored:    analysis/mosek_reg_5_cache/
    Ignored:    analysis/mosek_reg_6_cache/
    Ignored:    analysis/mosek_reg_cache/
    Ignored:    analysis/pihat0_null_cache/
    Ignored:    analysis/plot_diagnostic_cache/
    Ignored:    analysis/poster_obayes17_cache/
    Ignored:    analysis/real_data_simulation_2_cache/
    Ignored:    analysis/real_data_simulation_3_cache/
    Ignored:    analysis/real_data_simulation_4_cache/
    Ignored:    analysis/real_data_simulation_5_cache/
    Ignored:    analysis/real_data_simulation_cache/
    Ignored:    analysis/rmosek_primal_dual_2_cache/
    Ignored:    analysis/rmosek_primal_dual_cache/
    Ignored:    analysis/seqgendiff_cache/
    Ignored:    analysis/simulated_correlated_null_2_cache/
    Ignored:    analysis/simulated_correlated_null_3_cache/
    Ignored:    analysis/simulated_correlated_null_cache/
    Ignored:    analysis/simulation_real_se_2_cache/
    Ignored:    analysis/simulation_real_se_cache/
    Ignored:    analysis/smemo_2_cache/
    Ignored:    data/LSI/
    Ignored:    docs/.DS_Store
    Ignored:    docs/figure/.DS_Store
    Ignored:    output/fig/

</code></pre>
Note that any generated files, e.g. HTML, png, CSS, etc., are not included in this status report because it is ok for generated content to have uncommitted changes.
</details>
</li>
</ul>
<details>
<summary> <small><strong>Expand here to see past versions:</strong></small> </summary>
<ul>
<table style="border-collapse:separate; border-spacing:5px;">
<thead>
<tr>
<th style="text-align:left;">
File
</th>
<th style="text-align:left;">
Version
</th>
<th style="text-align:left;">
Author
</th>
<th style="text-align:left;">
Date
</th>
<th style="text-align:left;">
Message
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align:left;">
html
</td>
<td style="text-align:left;">
<a href="https://cdn.rawgit.com/LSun/truncash/e05bc836b3c74dc6ebca415afb5938675d6c5436/docs/mosek_reg.html" target="_blank">e05bc83</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2018-05-12
</td>
<td style="text-align:left;">
Update to 1.0
</td>
</tr>
<tr>
<td style="text-align:left;">
rmd
</td>
<td style="text-align:left;">
<a href="https://github.com/LSun/truncash/blob/cc0ab8379469bc3726f1508cd81e4ecd6fef1b1a/analysis/mosek_reg.rmd" target="_blank">cc0ab83</a>
</td>
<td style="text-align:left;">
Lei Sun
</td>
<td style="text-align:left;">
2018-05-11
</td>
<td style="text-align:left;">
update
</td>
</tr>
<tr>
<td style="text-align:left;">
html
</td>
<td style="text-align:left;">
<a href="https://cdn.rawgit.com/LSun/truncash/0f36d998db26444c5dd01502ea1af7fbd1129b22/docs/mosek_reg.html" target="_blank">0f36d99</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2017-12-21
</td>
<td style="text-align:left;">
Build site.
</td>
</tr>
<tr>
<td style="text-align:left;">
html
</td>
<td style="text-align:left;">
<a href="https://cdn.rawgit.com/LSun/truncash/853a484bfacf347e109f6c8fb3ffaab5f4d6cc02/docs/mosek_reg.html" target="_blank">853a484</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2017-11-07
</td>
<td style="text-align:left;">
Build site.
</td>
</tr>
<tr>
<td style="text-align:left;">
html
</td>
<td style="text-align:left;">
<a href="https://cdn.rawgit.com/LSun/truncash/1ea081a9eeb7fd3101271eeefe10ef8be9993622/docs/mosek_reg.html" target="_blank">1ea081a</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2017-07-03
</td>
<td style="text-align:left;">
sites
</td>
</tr>
<tr>
<td style="text-align:left;">
html
</td>
<td style="text-align:left;">
<a href="https://cdn.rawgit.com/LSun/truncash/899a5f8715e62e7f00fb6b334e5159c90ff672b4/docs/mosek_reg.html" target="_blank">899a5f8</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2017-05-09
</td>
<td style="text-align:left;">
mosek improvements
</td>
</tr>
<tr>
<td style="text-align:left;">
rmd
</td>
<td style="text-align:left;">
<a href="https://github.com/LSun/truncash/blob/1df916a921abfc4bf3504fdee5bc849e78b5b0d6/analysis/mosek_reg.rmd" target="_blank">1df916a</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2017-05-09
</td>
<td style="text-align:left;">
mosek improvement
</td>
</tr>
<tr>
<td style="text-align:left;">
html
</td>
<td style="text-align:left;">
<a href="https://cdn.rawgit.com/LSun/truncash/27bcaf9682ee32f9f548c6e5516f0c8ef684663c/docs/mosek_reg.html" target="_blank">27bcaf9</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2017-05-08
</td>
<td style="text-align:left;">
writeups
</td>
</tr>
<tr>
<td style="text-align:left;">
rmd
</td>
<td style="text-align:left;">
<a href="https://github.com/LSun/truncash/blob/6bac69e4ab027a161595872353a444b19769c794/analysis/mosek_reg.rmd" target="_blank">6bac69e</a>
</td>
<td style="text-align:left;">
LSun
</td>
<td style="text-align:left;">
2017-05-08
</td>
<td style="text-align:left;">
writeups
</td>
</tr>
</tbody>
</table>
</ul>
</details>
<hr />
<div id="introduction" class="section level2">
<h2>Introduction</h2>
<p>We are experimenting different ways to improve the performance of <code>Rmosek</code>, using typical data sets of correlated <span class="math inline">\(z\)</span> scores.</p>
<pre class="r"><code>z &lt;- read.table(&quot;../output/z_null_liver_777.txt&quot;)</code></pre>
<pre class="r"><code>sel &lt;- c(32, 327, 355, 483, 778)
ord &lt;- c(4, 9, 9, 4, 4)</code></pre>
<pre class="r"><code>source(&quot;../code/gdash.R&quot;)</code></pre>
</div>
<div id="algorithm-and-variations" class="section level2">
<h2>Algorithm and variations</h2>
<p>Recall that our <a href="ash_gd.html#optimization_problem">biconvex optimization problem</a> is as follows.</p>
<p><span class="math display">\[
\begin{array}{rl}
\min\limits_{\pi,w} &amp; -\sum\limits_{j = 1}^n\log\left(\sum\limits_{k = 1}^K\sum\limits_{l=1}^L\pi_k w_l f_{jkl} + \sum\limits_{k = 1}^K\pi_kf_{jk0}\right) - \sum\limits_{k = 1}^K\left(\lambda_k^\pi - 1\right)\log\pi_k + \sum\limits_{l = 1}^L\lambda_l^w\phi\left(\left|w_l\right|\right)
\\
\text{subject to} &amp; \sum\limits_{k = 1}^K\pi_k = 1\\
&amp; \sum\limits_{l=1}^L w_l \varphi^{(l)}\left(z\right) + \varphi\left(z\right) \geq 0, \forall z\in \mathbb{R}\\
&amp; w_l \text{ decay reasonably fast,}
\end{array}
\]</span> where <span class="math inline">\(- \sum\limits_{k = 1}^K\left(\lambda_k^\pi - 1\right)\log\pi_k\)</span> and <span class="math inline">\(+ \sum\limits_{l = 1}^L\lambda_l^w\phi\left(\left|w_l\right|\right)\)</span> are to regularize <span class="math inline">\(\pi_k\)</span> and <span class="math inline">\(w_l\)</span>, respectively.</p>
<p>This problem can be solved iteratively. Starting with an initial value, each step two convex optimization problems are solved.</p>
<p>With a given <span class="math inline">\(\hat w\)</span>, <span class="math inline">\(\hat\pi\)</span> is solved by</p>
<p><span class="math display">\[
\begin{array}{rl}
\min\limits_{\pi} &amp; -\sum\limits_{j = 1}^n\log\left(\sum\limits_{k = 1}^K\pi_k \left(\sum\limits_{l=1}^L \hat w_l f_{jkl} + f_{jk0}\right)\right) - \sum\limits_{k = 1}^K\left(\lambda_k^\pi - 1\right)\log\pi_k\\
\text{subject to} &amp; \sum\limits_{k = 1}^K\pi_k = 1 \  ,\\
\end{array}
\]</span></p>
<p>which is readily available with functions in <code>cvxr</code>.</p>
<p>Meanwhile, with a given <span class="math inline">\(\hat\pi\)</span>, the optimization problem to obtain <span class="math inline">\(\hat w\)</span> becomes</p>
<p><span class="math display">\[
\begin{array}{rl}
\min\limits_{w} &amp; -\sum\limits_{j = 1}^n\log\left(\sum\limits_{l=1}^Lw_l\left(\sum\limits_{k = 1}^K\hat\pi_k  f_{jkl}\right) + \sum\limits_{k = 1}^K\hat\pi_kf_{jk0}\right) + 
\sum\limits_{l = 1}^L\lambda_l^w
\phi
\left(\left|w_l\right|\right)
\\
\text{subject to} &amp; \sum\limits_{l=1}^L w_l \varphi^{(l)}\left(z\right) + \varphi\left(z\right) \geq 0, \forall z\in \mathbb{R}\\
&amp; w_l \text{ decay reasonably fast.}
\end{array}
\]</span> The two constraints are important to prevent <a href="gaussian_derivatives_3.html">numerical instability</a>. Yet they are not readily manifested as convex. Ideally, the regularization <span class="math inline">\(\sum\limits_{l = 1}^L\lambda_l^w\phi\left(\left|w_l\right|\right)\)</span> would be able to capture the essence of these two constaints, and at the same time maintain the convexity. Different ideas will be explored.</p>
<p>In this part, we’ll mainly work on the “basic form” of the <span class="math inline">\(w\)</span> optimization problem; that is, the optimization problem without regularization <span class="math inline">\(\sum\limits_{l = 1}^L\lambda_l^w\phi\left(\left|w_l\right|\right)\)</span>.</p>
<p>In the following, we’ll take a look at the basic form in its primal and dual formulations, optimized by <code>w.mosek()</code> and <code>w.mosek.primal</code> functions. First, they are applied to the correlated null, and their performance can be compared with <a href="gaussian_derivatives_2.html">the previous implementation</a> by <code>cvxr</code>. Then, they are applied to the simulated non-null data sets, and the results are compared with those obtained by <code>ASH</code>, as well as the truth.</p>
</div>
<div id="basic-form-primal" class="section level2">
<h2>Basic form: primal</h2>
<p>In its most basic form, the <span class="math inline">\(w\)</span> estimation problem is as follows.</p>
<p><span class="math display">\[
\begin{array}{rl}
\min\limits_{w} &amp; 
-\sum\limits_{j = 1}^n
\log\left(\sum\limits_{l=1}^Lw_l a_{jl} + a_{j0}\right) 
\\
\text{subject to} &amp; \sum\limits_{l=1}^Lw_l a_{jl} + a_{j0} \geq 0, \forall j \  .\\
\end{array}
\]</span> Let the matrix <span class="math inline">\(A = \left[a_{jl}\right]\)</span>, the vector <span class="math inline">\(a = \left[a_{j0}\right]\)</span>, and we have its equivalent form,</p>
<p><span class="math display">\[
\begin{array}{rl}
\min\limits_{w, g} &amp; 
-\sum\limits_{j = 1}^n
\log\left(g_j\right) 
\\
\text{subject to}
&amp; Aw + a = g \\
&amp; g \geq 0\  .
\end{array}
\]</span></p>
<p>This problem can be coded by <code>Rmosek</code> as a “separable convex optimization” (SCOPT) problem.</p>
<div id="correlated-null" class="section level3">
<h3>Correlated null</h3>
<pre><code>Fitted w: -0.03653526 0.1999284 0.01047094 -0.02012681 
Time Cost in Seconds: 7.945 2.884 13.152 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek primal fitting plotting-1.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.03394291 0.7345604 -0.1532514 0.1883912 -0.05504895 0.02297176 -0.006908406 0.001216017 -0.0003147927 
Time Cost in Seconds: 6.902 1.98 6.669 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek primal fitting plotting-2.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.02262546 0.9213963 0.02180428 0.1760983 -0.01379674 0.003968132 -0.004904973 -0.0006085249 -0.0002990675 
Time Cost in Seconds: 5.375 1.932 6.116 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek primal fitting plotting-3.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.04540484 -0.1275978 0.009150985 0.01004515 
Time Cost in Seconds: 19.294 2.066 14.959 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek primal fitting plotting-4.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.005943196 0.3980709 -0.009222458 0.02630697 
Time Cost in Seconds: 6.636 1.954 6.815 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek primal fitting plotting-5.png" width="672" style="display: block; margin: auto;" /></p>
</div>
<div id="signal-correlated-error" class="section level3">
<h3>Signal <span class="math inline">\(+\)</span> correlated error</h3>
<pre><code>Converged: FALSE 
Number of Iteration: 101 
Time Cost in Seconds: 2181.997 255.051 1644.499 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash primal signal plotting-1.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: FALSE 
Number of Iteration: 101 
Time Cost in Seconds: 2634.559 296.365 1970.452 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash primal signal plotting-2.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: TRUE 
Number of Iteration: 45 
Time Cost in Seconds: 553.188 127.588 540.733 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash primal signal plotting-3.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: TRUE 
Number of Iteration: 49 
Time Cost in Seconds: 781.062 126.839 622.938 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash primal signal plotting-4.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: FALSE 
Number of Iteration: 101 
Time Cost in Seconds: 2161.426 247.628 1565.216 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash primal signal plotting-5.png" width="672" style="display: block; margin: auto;" /></p>
</div>
</div>
<div id="basic-form-dual" class="section level2">
<h2>Basic form: dual</h2>
<p>The primal <span class="math inline">\(w\)</span> optimization problem has <span class="math inline">\(n + L\)</span> variables and <span class="math inline">\(n\)</span> constraints. When <span class="math inline">\(n\)</span> is large, such as <span class="math inline">\(n = 10K\)</span> in our simulations, the time cost is usually substantial. As the authors of <code>REBayes</code> pointed out, it’s better to work on the dual form, which is</p>
<p><span class="math display">\[
\begin{array}{rl}
\min\limits_{v} &amp; 
-\sum\limits_{j = 1}^n
\log\left(v_j\right) + a^Tv
\\
\text{subject to}
&amp; A^Tv = 0 \\
&amp; v \geq 0\  .
\end{array}
\]</span> The dual form has <span class="math inline">\(n\)</span> variables and more importantly, only <span class="math inline">\(L\)</span> constraints. As <span class="math inline">\(L \ll n\)</span>, the dual form is far more computationally efficient.</p>
<p><code>Rmosek</code> provides optimal solutions to both primal and dual variables, so <span class="math inline">\(\hat w\)</span> is readily available when working on <span class="math inline">\(v\)</span> optimization. But we need to be careful on which dual variables to use, such as <code>$sol$itr$suc</code>, <code>$sol$itr$slc</code>, or others.</p>
<div id="correlated-null-1" class="section level3">
<h3>Correlated null</h3>
<pre><code>Fitted w: -0.03642797 0.1971637 0.01074601 -0.02181494 
Time Cost in Seconds: 0.485 0.049 0.388 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek dual fitting plotting-1.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.03361434 0.7339189 -0.1544144 0.1875235 -0.0560049 0.02267003 -0.007151714 0.001187682 -0.0003321398 
Time Cost in Seconds: 0.524 0.009 0.372 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek dual fitting plotting-2.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.02273596 0.9206369 0.02224234 0.1750273 -0.01339113 0.003607418 -0.004794795 -0.0006395078 -0.0002908422 
Time Cost in Seconds: 0.529 0.008 0.375 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek dual fitting plotting-3.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.04544396 -0.1272823 0.008811108 0.009915311 
Time Cost in Seconds: 0.448 0.006 0.322 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek dual fitting plotting-4.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Fitted w: 0.006084177 0.3976595 -0.009103231 0.02610567 
Time Cost in Seconds: 0.489 0.005 0.313 </code></pre>
<p><img src="figure/mosek_reg.rmd/Rmosek dual fitting plotting-5.png" width="672" style="display: block; margin: auto;" /></p>
</div>
<div id="signal-correlated-error-1" class="section level3">
<h3>Signal <span class="math inline">\(+\)</span> correlated error</h3>
<pre><code>Converged: TRUE 
Number of Iteration: 21 
Time Cost in Seconds: 46.978 2.71 29.017 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash dual signal plotting-1.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: TRUE 
Number of Iteration: 21 
Time Cost in Seconds: 45.406 5.343 52.01 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash dual signal plotting-2.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: TRUE 
Number of Iteration: 16 
Time Cost in Seconds: 34.293 3.519 26.79 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash dual signal plotting-3.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: TRUE 
Number of Iteration: 31 
Time Cost in Seconds: 64.198 3.902 39.897 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash dual signal plotting-4.png" width="672" style="display: block; margin: auto;" /></p>
<pre><code>Converged: TRUE 
Number of Iteration: 12 
Time Cost in Seconds: 27.247 1.446 15.392 </code></pre>
<p><img src="figure/mosek_reg.rmd/gdash dual signal plotting-5.png" width="672" style="display: block; margin: auto;" /></p>
</div>
</div>
<div id="conclusion" class="section level2">
<h2>Conclusion</h2>
<p>Implementation by <code>Rmosek</code> can fully reproduce the results obtained by <code>cvxr</code>. Moreover, the dual form gives the same results as the primal dorm does, with only a fraction of time.</p>
<p>It seems hopeful that we’ll find a key to successfully tackle correlation in simultaneous inference, which has eluded Prof. Brad Efron for more than a decade.</p>
</div>
<div id="session-information" class="section level2">
<h2>Session information</h2>
<pre class="r"><code>sessionInfo()</code></pre>
<pre><code>R version 3.4.3 (2017-11-30)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS High Sierra 10.13.4

Matrix products: default
BLAS: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRblas.0.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] Rmosek_8.0.69     PolynomF_1.0-1    CVXR_0.95         REBayes_1.2      
[5] Matrix_1.2-12     SQUAREM_2017.10-1 EQL_1.0-0         ttutils_1.0-1    

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.16      knitr_1.20        whisker_0.3-2    
 [4] magrittr_1.5      workflowr_1.0.1   bit_1.1-12       
 [7] lattice_0.20-35   R6_2.2.2          stringr_1.3.0    
[10] tools_3.4.3       grid_3.4.3        R.oo_1.21.0      
[13] git2r_0.21.0      scs_1.1-1         htmltools_0.3.6  
[16] bit64_0.9-7       yaml_2.1.18       rprojroot_1.3-2  
[19] digest_0.6.15     gmp_0.5-13.1      ECOSolveR_0.4    
[22] R.utils_2.6.0     evaluate_0.10.1   rmarkdown_1.9    
[25] stringi_1.1.6     Rmpfr_0.6-1       compiler_3.4.3   
[28] backports_1.1.2   R.methodsS3_1.7.1</code></pre>
</div>

<!-- Adjust MathJax settings so that all math formulae are shown using
TeX fonts only; see
http://docs.mathjax.org/en/latest/configuration.html.  This will make
the presentation more consistent at the cost of the webpage sometimes
taking slightly longer to load. Note that this only works because the
footer is added to webpages before the MathJax javascript. -->
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({
    "HTML-CSS": { availableFonts: ["TeX"] }
  });
</script>

<hr>
<p>
  This reproducible <a href="http://rmarkdown.rstudio.com">R Markdown</a>
  analysis was created with
  <a href="https://github.com/jdblischak/workflowr">workflowr</a> 1.0.1
</p>
<hr>


</div>
</div>

</div>

<script>

// add bootstrap table styles to pandoc tables
function bootstrapStylePandocTables() {
  $('tr.header').parent('thead').parent('table').addClass('table table-condensed');
}
$(document).ready(function () {
  bootstrapStylePandocTables();
});


</script>

<!-- dynamically load mathjax for compatibility with self-contained -->
<script>
  (function () {
    var script = document.createElement("script");
    script.type = "text/javascript";
    script.src  = "https://mathjax.rstudio.com/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML";
    document.getElementsByTagName("head")[0].appendChild(script);
  })();
</script>

</body>
</html>