blob: de1ddeb2dbe4d44f378721abd87d21896db24092 [file] [log] [blame]
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8"/>
<meta content="IE=edge" http-equiv="X-UA-Compatible"/>
<meta content="width=device-width, initial-scale=1" name="viewport"/>
<title>Data Loading API — mxnet documentation</title>
<link crossorigin="anonymous" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" rel="stylesheet"/>
<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css" rel="stylesheet"/>
<link href="../../_static/basic.css" rel="stylesheet" type="text/css"/>
<link href="../../_static/pygments.css" rel="stylesheet" type="text/css"/>
<link href="../../_static/mxnet.css" rel="stylesheet" type="text/css">
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: '../../',
VERSION: '',
COLLAPSE_INDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true,
SOURCELINK_SUFFIX: ''
};
</script>
<script src="../../_static/jquery-1.11.1.js" type="text/javascript"></script>
<script src="../../_static/underscore.js" type="text/javascript"></script>
<script src="../../_static/searchtools_custom.js" type="text/javascript"></script>
<script src="../../_static/doctools.js" type="text/javascript"></script>
<script src="../../_static/selectlang.js" type="text/javascript"></script>
<script src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML" type="text/javascript"></script>
<script type="text/javascript"> jQuery(function() { Search.loadIndex("/searchindex.js"); Search.init();}); </script>
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new
Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-96378503-1', 'auto');
ga('send', 'pageview');
</script>
<!-- -->
<!-- <script type="text/javascript" src="../../_static/jquery.js"></script> -->
<!-- -->
<!-- <script type="text/javascript" src="../../_static/underscore.js"></script> -->
<!-- -->
<!-- <script type="text/javascript" src="../../_static/doctools.js"></script> -->
<!-- -->
<!-- <script type="text/javascript" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script> -->
<!-- -->
<link href="index.html" rel="up" title="MXNet - Perl API"/>
<link href="ndarray.html" rel="next" title="NDArray API">
<link href="symbol.html" rel="prev" title="MXNet Perl Symbolic API">
<link href="https://raw.githubusercontent.com/dmlc/web-data/master/mxnet/image/mxnet-icon.png" rel="icon" type="image/png"/>
</link></link></link></head>
<body background="https://raw.githubusercontent.com/dmlc/web-data/master/mxnet/image/mxnet-background-compressed.jpeg" role="document">
<div class="content-block"><div class="navbar navbar-fixed-top">
<div class="container" id="navContainer">
<div class="innder" id="header-inner">
<h1 id="logo-wrap">
<a href="../../" id="logo"><img src="https://raw.githubusercontent.com/dmlc/web-data/master/mxnet/image/mxnet_logo.png"/></a>
</h1>
<nav class="nav-bar" id="main-nav">
<a class="main-nav-link" href="../../install/index.html">Install</a>
<a class="main-nav-link" href="../../tutorials/index.html">Tutorials</a>
<span id="dropdown-menu-position-anchor">
<a aria-expanded="true" aria-haspopup="true" class="main-nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button">Gluon <span class="caret"></span></a>
<ul class="dropdown-menu navbar-menu" id="package-dropdown-menu">
<li><a class="main-nav-link" href="../../gluon/index.html">About</a></li>
<li><a class="main-nav-link" href="http://gluon.mxnet.io">Tutorials</a></li>
</ul>
</span>
<span id="dropdown-menu-position-anchor">
<a aria-expanded="true" aria-haspopup="true" class="main-nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button">API <span class="caret"></span></a>
<ul class="dropdown-menu navbar-menu" id="package-dropdown-menu">
<li><a class="main-nav-link" href="../../api/python/index.html">Python</a></li>
<li><a class="main-nav-link" href="../../api/scala/index.html">Scala</a></li>
<li><a class="main-nav-link" href="../../api/r/index.html">R</a></li>
<li><a class="main-nav-link" href="../../api/julia/index.html">Julia</a></li>
<li><a class="main-nav-link" href="../../api/c++/index.html">C++</a></li>
<li><a class="main-nav-link" href="../../api/perl/index.html">Perl</a></li>
</ul>
</span>
<span id="dropdown-menu-position-anchor-docs">
<a aria-expanded="true" aria-haspopup="true" class="main-nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button">Docs <span class="caret"></span></a>
<ul class="dropdown-menu navbar-menu" id="package-dropdown-menu-docs">
<li><a class="main-nav-link" href="../../faq/index.html">FAQ</a></li>
<li><a class="main-nav-link" href="../../architecture/index.html">Architecture</a></li>
<li><a class="main-nav-link" href="https://github.com/apache/incubator-mxnet/tree/0.12.1/example">Examples</a></li>
<li><a class="main-nav-link" href="../../model_zoo/index.html">Model Zoo</a></li>
</ul>
</span>
<a class="main-nav-link" href="https://github.com/dmlc/mxnet">Github</a>
<span id="dropdown-menu-position-anchor-community">
<a aria-expanded="true" aria-haspopup="true" class="main-nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button">Community <span class="caret"></span></a>
<ul class="dropdown-menu navbar-menu" id="package-dropdown-menu-community">
<li><a class="main-nav-link" href="../../community/index.html">Community</a></li>
<li><a class="main-nav-link" href="../../community/contribute.html">Contribute</a></li>
<li><a class="main-nav-link" href="../../community/powered_by.html">Powered By</a></li>
</ul>
</span>
<a class="main-nav-link" href="http://discuss.mxnet.io">Discuss</a>
<span id="dropdown-menu-position-anchor-version" style="position: relative"><a href="#" class="main-nav-link dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="true">Versions(0.12.1)<span class="caret"></span></a><ul id="package-dropdown-menu" class="dropdown-menu"><li><a class="main-nav-link" href=https://mxnet.incubator.apache.org/>1.0.0</a></li><li><a class="main-nav-link" href=https://mxnet.incubator.apache.org/versions/0.12.1/index.html>0.12.1</a></li><li><a class="main-nav-link" href=https://mxnet.incubator.apache.org/versions/0.12.0/index.html>0.12.0</a></li><li><a class="main-nav-link" href=https://mxnet.incubator.apache.org/versions/0.11.0/index.html>0.11.0</a></li><li><a class="main-nav-link" href=https://mxnet.incubator.apache.org/versions/master/index.html>master</a></li></ul></span></nav>
<script> function getRootPath(){ return "../../" } </script>
<div class="burgerIcon dropdown">
<a class="dropdown-toggle" data-toggle="dropdown" href="#" role="button"></a>
<ul class="dropdown-menu" id="burgerMenu">
<li><a href="../../install/index.html">Install</a></li>
<li><a class="main-nav-link" href="../../tutorials/index.html">Tutorials</a></li>
<li class="dropdown-submenu">
<a href="#" tabindex="-1">Community</a>
<ul class="dropdown-menu">
<li><a href="../../community/index.html" tabindex="-1">Community</a></li>
<li><a href="../../community/contribute.html" tabindex="-1">Contribute</a></li>
<li><a href="../../community/powered_by.html" tabindex="-1">Powered By</a></li>
</ul>
</li>
<li class="dropdown-submenu">
<a href="#" tabindex="-1">API</a>
<ul class="dropdown-menu">
<li><a href="../../api/python/index.html" tabindex="-1">Python</a>
</li>
<li><a href="../../api/scala/index.html" tabindex="-1">Scala</a>
</li>
<li><a href="../../api/r/index.html" tabindex="-1">R</a>
</li>
<li><a href="../../api/julia/index.html" tabindex="-1">Julia</a>
</li>
<li><a href="../../api/c++/index.html" tabindex="-1">C++</a>
</li>
<li><a href="../../api/perl/index.html" tabindex="-1">Perl</a>
</li>
</ul>
</li>
<li class="dropdown-submenu">
<a href="#" tabindex="-1">Docs</a>
<ul class="dropdown-menu">
<li><a href="../../tutorials/index.html" tabindex="-1">Tutorials</a></li>
<li><a href="../../faq/index.html" tabindex="-1">FAQ</a></li>
<li><a href="../../architecture/index.html" tabindex="-1">Architecture</a></li>
<li><a href="https://github.com/apache/incubator-mxnet/tree/0.12.1/example" tabindex="-1">Examples</a></li>
<li><a href="../../model_zoo/index.html" tabindex="-1">Model Zoo</a></li>
</ul>
</li>
<li><a href="../../architecture/index.html">Architecture</a></li>
<li><a class="main-nav-link" href="https://github.com/dmlc/mxnet">Github</a></li>
<li id="dropdown-menu-position-anchor-version-mobile" class="dropdown-submenu" style="position: relative"><a href="#" tabindex="-1">Versions(0.12.1)</a><ul class="dropdown-menu"><li><a tabindex="-1" href=https://mxnet.incubator.apache.org/>1.0.0</a></li><li><a tabindex="-1" href=https://mxnet.incubator.apache.org/versions/0.12.1/index.html>0.12.1</a></li><li><a tabindex="-1" href=https://mxnet.incubator.apache.org/versions/0.12.0/index.html>0.12.0</a></li><li><a tabindex="-1" href=https://mxnet.incubator.apache.org/versions/0.11.0/index.html>0.11.0</a></li><li><a tabindex="-1" href=https://mxnet.incubator.apache.org/versions/master/index.html>master</a></li></ul></li></ul>
</div>
<div class="plusIcon dropdown">
<a class="dropdown-toggle" data-toggle="dropdown" href="#" role="button"><span aria-hidden="true" class="glyphicon glyphicon-plus"></span></a>
<ul class="dropdown-menu dropdown-menu-right" id="plusMenu"></ul>
</div>
<div id="search-input-wrap">
<form action="../../search.html" autocomplete="off" class="" method="get" role="search">
<div class="form-group inner-addon left-addon">
<i class="glyphicon glyphicon-search"></i>
<input class="form-control" name="q" placeholder="Search" type="text"/>
</div>
<input name="check_keywords" type="hidden" value="yes"/>
<input name="area" type="hidden" value="default">
</input></form>
<div id="search-preview"></div>
</div>
<div id="searchIcon">
<span aria-hidden="true" class="glyphicon glyphicon-search"></span>
</div>
<!-- <div id="lang-select-wrap"> -->
<!-- <label id="lang-select-label"> -->
<!-- <\!-- <i class="fa fa-globe"></i> -\-> -->
<!-- <span></span> -->
<!-- </label> -->
<!-- <select id="lang-select"> -->
<!-- <option value="en">Eng</option> -->
<!-- <option value="zh">中文</option> -->
<!-- </select> -->
<!-- </div> -->
<!-- <a id="mobile-nav-toggle">
<span class="mobile-nav-toggle-bar"></span>
<span class="mobile-nav-toggle-bar"></span>
<span class="mobile-nav-toggle-bar"></span>
</a> -->
</div>
</div>
</div>
<script type="text/javascript">
$('body').css('background', 'white');
</script>
<div class="container">
<div class="row">
<div aria-label="main navigation" class="sphinxsidebar leftsidebar" role="navigation">
<div class="sphinxsidebarwrapper">
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="../python/index.html">Python Documents</a></li>
<li class="toctree-l1"><a class="reference internal" href="../r/index.html">R Documents</a></li>
<li class="toctree-l1"><a class="reference internal" href="../julia/index.html">Julia Documents</a></li>
<li class="toctree-l1"><a class="reference internal" href="../c++/index.html">C++ Documents</a></li>
<li class="toctree-l1"><a class="reference internal" href="../scala/index.html">Scala Documents</a></li>
<li class="toctree-l1 current"><a class="reference internal" href="index.html">Perl Documents</a><ul class="current">
<li class="toctree-l2 current"><a class="reference internal" href="index.html#perl-api-reference">Perl API Reference</a><ul class="current">
<li class="toctree-l3"><a class="reference internal" href="module.html">Module API is a flexible high-level interface for training neural networks.</a></li>
<li class="toctree-l3"><a class="reference internal" href="symbol.html">Symbolic API performs operations on NDArrays to assemble neural networks from layers.</a></li>
<li class="toctree-l3 current"><a class="current reference internal" href="">IO Data Loading API performs parsing and data loading.</a><ul>
<li class="toctree-l4"><a class="reference internal" href="#overview">Overview</a></li>
<li class="toctree-l4"><a class="reference internal" href="#predefined-data-iterators">Predefined Data iterators</a></li>
<li class="toctree-l4"><a class="reference internal" href="#helper-classes-and-functions">Helper classes and functions</a></li>
<li class="toctree-l4"><a class="reference internal" href="#develop-a-new-iterator">Develop a new iterator</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="ndarray.html">NDArray API performs vector/matrix/tensor operations.</a></li>
<li class="toctree-l3"><a class="reference internal" href="kvstore.html">KVStore API performs multi-GPU and multi-host distributed training.</a></li>
</ul>
</li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../../faq/index.html">HowTo Documents</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../architecture/index.html">System Documents</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../tutorials/index.html">Tutorials</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../community/index.html">Community</a></li>
</ul>
</div>
</div>
<div class="content">
<div class="page-tracker"></div>
<div class="section" id="data-loading-api">
<span id="data-loading-api"></span><h1>Data Loading API<a class="headerlink" href="#data-loading-api" title="Permalink to this headline"></a></h1>
<div class="section" id="overview">
<span id="overview"></span><h2>Overview<a class="headerlink" href="#overview" title="Permalink to this headline"></a></h2>
<p>A data iterator reads data batch by batch.</p>
<div class="highlight-perl"><div class="highlight"><pre><span></span><span class="n">pdl</span><span class="o">></span> <span class="nv">$data</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">nd</span><span class="o">-></span><span class="n">ones</span><span class="p">([</span><span class="mi">100</span><span class="p">,</span><span class="mi">10</span><span class="p">])</span>
<span class="n">pdl</span><span class="o">></span> <span class="nv">$nd_iter</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">io</span><span class="o">-></span><span class="n">NDArrayIter</span><span class="p">(</span><span class="nv">$data</span><span class="p">,</span> <span class="n">batch_size</span><span class="o">=></span><span class="mi">25</span><span class="p">)</span>
<span class="n">pdl</span><span class="o">></span> <span class="k">for</span> <span class="k">my</span> <span class="nv">$batch</span> <span class="p">(</span><span class="nv">@</span><span class="p">{</span> <span class="nv">$nd_iter</span> <span class="p">})</span> <span class="p">{</span> <span class="k">print</span> <span class="nv">$batch</span><span class="o">-></span><span class="nn">data</span><span class="o">-></span><span class="p">[</span><span class="mi">0</span><span class="p">],</span><span class="s">"\n"</span> <span class="p">}</span>
<span class="o"><</span><span class="nn">AI::MXNet::</span><span class="n">NDArray</span> <span class="mi">25</span><span class="n">x10</span> <span class="nv">@cpu</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span><span class="o">></span>
<span class="o"><</span><span class="nn">AI::MXNet::</span><span class="n">NDArray</span> <span class="mi">25</span><span class="n">x10</span> <span class="nv">@cpu</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span><span class="o">></span>
<span class="o"><</span><span class="nn">AI::MXNet::</span><span class="n">NDArray</span> <span class="mi">25</span><span class="n">x10</span> <span class="nv">@cpu</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span><span class="o">></span>
<span class="o"><</span><span class="nn">AI::MXNet::</span><span class="n">NDArray</span> <span class="mi">25</span><span class="n">x10</span> <span class="nv">@cpu</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span><span class="o">></span>
</pre></div>
</div>
<p>If <code class="docutils literal"><span class="pre">$nd_iter->reset()</span></code> is called, then reads the data again from beginning.</p>
<p>In addition, an iterator provides information about the batch, including the
shapes and name.</p>
<div class="highlight-perl"><div class="highlight"><pre><span></span><span class="n">pdl</span><span class="o">></span> <span class="nv">$nd_iter</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">io</span><span class="o">-></span><span class="n">NDArrayIter</span><span class="p">(</span><span class="n">data</span><span class="o">=></span><span class="p">{</span><span class="n">data</span> <span class="o">=></span> <span class="nn">mx</span><span class="o">-></span><span class="nn">nd</span><span class="o">-></span><span class="n">ones</span><span class="p">([</span><span class="mi">100</span><span class="p">,</span><span class="mi">10</span><span class="p">])},</span> <span class="n">label</span><span class="o">=></span><span class="p">{</span><span class="n">softmax_label</span> <span class="o">=></span> <span class="nn">mx</span><span class="o">-></span><span class="nn">nd</span><span class="o">-></span><span class="n">ones</span><span class="p">([</span><span class="mi">100</span><span class="p">])},</span> <span class="n">batch_size</span><span class="o">=></span><span class="mi">25</span><span class="p">)</span>
<span class="n">pdl</span><span class="o">></span> <span class="k">print</span><span class="p">(</span><span class="nv">$nd_iter</span><span class="o">-></span><span class="nn">provide_data</span><span class="o">-></span><span class="p">[</span><span class="mi">0</span><span class="p">],</span><span class="s">"\n"</span><span class="p">)</span>
<span class="n">DataDesc</span><span class="p">[</span><span class="n">data</span><span class="p">,</span><span class="mi">25</span><span class="n">x10</span><span class="p">,</span><span class="n">float32</span><span class="p">,</span><span class="n">NCHW</span><span class="p">]</span>
<span class="n">pdl</span><span class="o">></span> <span class="k">print</span><span class="p">(</span><span class="nv">$nd_iter</span><span class="o">-></span><span class="nn">provide_label</span><span class="o">-></span><span class="p">[</span><span class="mi">0</span><span class="p">],</span><span class="s">"\n"</span><span class="p">)</span>
<span class="n">DataDesc</span><span class="p">[</span><span class="n">softmax_label</span><span class="p">,</span><span class="mi">25</span><span class="p">,</span><span class="n">float32</span><span class="p">,</span><span class="n">NCHW</span><span class="p">]</span>
</pre></div>
</div>
<p>So this iterator can be used to train a symbol whose input data variable has
name <code class="docutils literal"><span class="pre">data</span></code> and input label variable has name <code class="docutils literal"><span class="pre">softmax_label</span></code>.</p>
<div class="highlight-perl"><div class="highlight"><pre><span></span><span class="n">pdl</span><span class="o">></span> <span class="nv">$data</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">sym</span><span class="o">-></span><span class="n">Variable</span><span class="p">(</span><span class="s">'data'</span><span class="p">)</span>
<span class="n">pdl</span><span class="o">></span> <span class="nv">$label</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">sym</span><span class="o">-></span><span class="n">Variable</span><span class="p">(</span><span class="s">'softmax_label'</span><span class="p">)</span>
<span class="n">pdl</span><span class="o">></span> <span class="nv">$fullc</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">sym</span><span class="o">-></span><span class="n">FullyConnected</span><span class="p">(</span><span class="n">data</span><span class="o">=></span><span class="nv">$data</span><span class="p">,</span> <span class="n">num_hidden</span><span class="o">=></span><span class="mi">1</span><span class="p">)</span>
<span class="n">pdl</span><span class="o">></span> <span class="nv">$loss</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">sym</span><span class="o">-></span><span class="n">SoftmaxOutput</span><span class="p">(</span><span class="n">data</span><span class="o">=></span><span class="nv">$data</span><span class="p">,</span> <span class="n">label</span><span class="o">=></span><span class="nv">$label</span><span class="p">)</span>
<span class="n">pdl</span><span class="o">></span> <span class="nv">$mod</span> <span class="o">=</span> <span class="nn">mx</span><span class="o">-></span><span class="nn">mod</span><span class="o">-></span><span class="n">Module</span><span class="p">(</span><span class="nv">$loss</span><span class="p">)</span>
<span class="n">pdl</span><span class="o">></span> <span class="k">print</span><span class="p">(</span><span class="nv">$mod</span><span class="o">-></span><span class="nn">data_names</span><span class="o">-></span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="n">data</span>
<span class="n">pdl</span><span class="o">></span> <span class="k">print</span><span class="p">(</span><span class="nv">$mod</span><span class="o">-></span><span class="nn">label_names</span><span class="o">-></span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="n">softmax_label</span>
<span class="n">pdl</span><span class="o">></span> <span class="nv">$mod</span><span class="o">-></span><span class="nb">bind</span><span class="p">(</span><span class="n">data_shapes</span><span class="o">=></span><span class="nv">$nd_iter</span><span class="o">-></span><span class="n">provide_data</span><span class="p">,</span> <span class="n">label_shapes</span><span class="o">=></span><span class="nv">$nd_iter</span><span class="o">-></span><span class="n">provide_label</span><span class="p">)</span>
</pre></div>
</div>
<p>Then we can call <code class="docutils literal"><span class="pre">$mod->fit($nd_iter,</span> <span class="pre">num_epoch=>2)</span></code> to train <code class="docutils literal"><span class="pre">loss</span></code> by 2 epochs.</p>
</div>
<div class="section" id="predefined-data-iterators">
<span id="predefined-data-iterators"></span><h2>Predefined Data iterators<a class="headerlink" href="#predefined-data-iterators" title="Permalink to this headline"></a></h2>
<div class="highlight-perl"><div class="highlight"><pre><span></span><span class="nn">mx</span><span class="o">-></span><span class="nn">io</span><span class="o">-></span><span class="n">NDArrayIter</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">io</span><span class="o">-></span><span class="n">CSVIter</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">io</span><span class="o">-></span><span class="n">ImageRecordIter</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">io</span><span class="o">-></span><span class="n">ImageRecordUInt8Iter</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">io</span><span class="o">-></span><span class="n">MNISTIter</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">recordio</span><span class="o">-></span><span class="n">MXRecordIO</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">recordio</span><span class="o">-></span><span class="n">MXIndexedRecordIO</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">ImageIter</span>
</pre></div>
</div>
</div>
<div class="section" id="helper-classes-and-functions">
<span id="helper-classes-and-functions"></span><h2>Helper classes and functions<a class="headerlink" href="#helper-classes-and-functions" title="Permalink to this headline"></a></h2>
<p>Data structures and other iterators provided in the <code class="docutils literal"><span class="pre">AI::MXNet::IO</span></code> package.</p>
<div class="highlight-perl"><div class="highlight"><pre><span></span><span class="nn">AI::MXNet::</span><span class="n">DataDesc</span>
<span class="nn">AI::MXNet::</span><span class="n">DataBatch</span>
<span class="nn">AI::MXNet::</span><span class="n">DataIter</span>
<span class="nn">AI::MXNet::</span><span class="n">ResizeIter</span>
<span class="nn">AI::MXNet::</span><span class="n">MXDataIter</span>
</pre></div>
</div>
<p>A list of image modification functions provided by <code class="docutils literal"><span class="pre">AI::MXNet::Image</span></code>.</p>
<div class="highlight-perl"><div class="highlight"><pre><span></span><span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">imdecode</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">scale_down</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">resize_short</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">fixed_crop</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">random_crop</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">center_crop</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">color_normalize</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">random_size_crop</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">ResizeAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">RandomCropAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">RandomSizedCropAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">CenterCropAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">RandomOrderAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">ColorJitterAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">LightingAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">ColorNormalizeAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">HorizontalFlipAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">CastAug</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">image</span><span class="o">-></span><span class="n">CreateAugmenter</span>
</pre></div>
</div>
<p>Functions to read and write RecordIO files.</p>
<div class="highlight-perl"><div class="highlight"><pre><span></span><span class="nn">mx</span><span class="o">-></span><span class="nn">recordio</span><span class="o">-></span><span class="nb">pack</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">recordio</span><span class="o">-></span><span class="nb">unpack</span>
<span class="nn">mx</span><span class="o">-></span><span class="nn">recordio</span><span class="o">-></span><span class="n">unpack_img</span>
</pre></div>
</div>
</div>
<div class="section" id="develop-a-new-iterator">
<span id="develop-a-new-iterator"></span><h2>Develop a new iterator<a class="headerlink" href="#develop-a-new-iterator" title="Permalink to this headline"></a></h2>
<p>Writing a new data iterator in Perl is straightforward. Most MXNet
training/inference programs accept an object with <code class="docutils literal"><span class="pre">provide_data</span></code>
and <code class="docutils literal"><span class="pre">provide_label</span></code> properties.
Please refer to AI-MXNet/examples for the examples of custom iterators.</p>
</div>
</div>
</div>
</div>
<div aria-label="main navigation" class="sphinxsidebar rightsidebar" role="navigation">
<div class="sphinxsidebarwrapper">
<h3><a href="../../index.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">Data Loading API</a><ul>
<li><a class="reference internal" href="#overview">Overview</a></li>
<li><a class="reference internal" href="#predefined-data-iterators">Predefined Data iterators</a></li>
<li><a class="reference internal" href="#helper-classes-and-functions">Helper classes and functions</a></li>
<li><a class="reference internal" href="#develop-a-new-iterator">Develop a new iterator</a></li>
</ul>
</li>
</ul>
</div>
</div>
</div><div class="footer">
<div class="section-disclaimer">
<div class="container">
<div>
<img height="60" src="https://raw.githubusercontent.com/dmlc/web-data/master/mxnet/image/apache_incubator_logo.png"/>
<p>
Apache MXNet is an effort undergoing incubation at The Apache Software Foundation (ASF), <strong>sponsored by the <i>Apache Incubator</i></strong>. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects. While incubation status is not necessarily a reflection of the completeness or stability of the code, it does indicate that the project has yet to be fully endorsed by the ASF.
</p>
<p>
"Copyright © 2017, The Apache Software Foundation
Apache MXNet, MXNet, Apache, the Apache feather, and the Apache MXNet project logo are either registered trademarks or trademarks of the Apache Software Foundation."
</p>
</div>
</div>
</div>
</div> <!-- pagename != index -->
</div>
<script crossorigin="anonymous" integrity="sha384-0mSbJDEHialfmuBBQP6A4Qrprq5OVfW37PRR3j5ELqxss1yVqOtnepnHVP9aJ7xS" src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script src="../../_static/js/sidebar.js" type="text/javascript"></script>
<script src="../../_static/js/search.js" type="text/javascript"></script>
<script src="../../_static/js/navbar.js" type="text/javascript"></script>
<script src="../../_static/js/clipboard.min.js" type="text/javascript"></script>
<script src="../../_static/js/copycode.js" type="text/javascript"></script>
<script src="../../_static/js/page.js" type="text/javascript"></script>
<script type="text/javascript">
$('body').ready(function () {
$('body').css('visibility', 'visible');
});
</script>
</body>
</html>