http://code.activestate.com/recipes/tags/back/2014-09-11T06:25:14-07:00ActiveState Code Recipes2014-09-11T06:25:14-07:00Alexander Pletzerhttp://code.activestate.com/recipes/users/4190754/http://code.activestate.com/recipes/578932-teach-your-computer-a-few-tricks/

<p style="color: grey"> Python recipe 578932 by <a href="/recipes/users/4190754/">Alexander Pletzer</a> (<a href="/recipes/tags/anl/">anl</a>, <a href="/recipes/tags/back/">back</a>, <a href="/recipes/tags/network/">network</a>, <a href="/recipes/tags/neural/">neural</a>, <a href="/recipes/tags/propagation/">propagation</a>). </p> <p>Following is an artifical neural network program that takes any number of inputs and any number of hidden layers, and spits out an output. It applies back propagation with regularization to minimize the cost function. A gradient descent algorithm tries to find the minimum of the cost function in the landscape of weights. </p>

2012-05-30T17:09:49-07:00David Adlerhttp://code.activestate.com/recipes/users/4182015/http://code.activestate.com/recipes/578148-simple-back-propagation-neural-network-in-python-s/

<p style="color: grey"> Python recipe 578148 by <a href="/recipes/users/4182015/">David Adler</a> (<a href="/recipes/tags/back/">back</a>, <a href="/recipes/tags/back_propagation/">back_propagation</a>, <a href="/recipes/tags/neural/">neural</a>, <a href="/recipes/tags/neural_network/">neural_network</a>, <a href="/recipes/tags/propagation/">propagation</a>, <a href="/recipes/tags/python/">python</a>). </p> <p>This is a slightly different version of this <a href="http://arctrix.com/nas/python/bpnn.py" rel="nofollow">http://arctrix.com/nas/python/bpnn.py</a></p>

2012-04-26T10:37:10-07:00Thomas Lehmannhttp://code.activestate.com/recipes/users/4174477/http://code.activestate.com/recipes/578113-human-readable-format-for-a-given-time-delta/

<p style="color: grey"> Python recipe 578113 by <a href="/recipes/users/4174477/">Thomas Lehmann</a> (<a href="/recipes/tags/back/">back</a>, <a href="/recipes/tags/date/">date</a>, <a href="/recipes/tags/human/">human</a>, <a href="/recipes/tags/readable/">readable</a>, <a href="/recipes/tags/time/">time</a>). </p> <p><strong>What is it about?</strong></p> <ul> <li>I need to say someting like <em>1 day ago</em>, <em>5 days ago</em>, <em>2 weeks ago</em>, ...</li> <li>I can control to have it with/without milliseconds and microseconds.</li> <li>I can use it automatically with current date and time or with a provide one.</li> </ul> <p><strong>Why?</strong></p> <ul> <li>I need it for next revision of my <a href="http://code.activestate.com/recipes/578111/">recipe 578111</a>.</li> <li>I found recipes here and there but often it is always assumed that a month has 30 days and that a year has 365 days; this is not true. That's why I've left away months and years.</li> </ul>