<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Returns the activation steepness for supplied neuron and layer number</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.fann-get-activation-function.html">fann_get_activation_function</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.fann-get-bias-array.html">fann_get_bias_array</a></div> <div class="up"><a href="ref.fann.html">Fann Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.fann-get-activation-steepness" class="refentry"> <div class="refnamediv"> <h1 class="refname">fann_get_activation_steepness</h1> <p class="verinfo">(PECL fann >= 1.0.0)</p><p class="refpurpose"><span class="refname">fann_get_activation_steepness</span> — <span class="dc-title">Returns the activation steepness for supplied neuron and layer number</span></p> </div> <div class="refsect1 description" id="refsect1-function.fann-get-activation-steepness-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">float</span> <span class="methodname"><strong>fann_get_activation_steepness</strong></span> ( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$ann</code></span> , <span class="methodparam"><span class="type">int</span> <code class="parameter">$layer</code></span> , <span class="methodparam"><span class="type">int</span> <code class="parameter">$neuron</code></span> )</div> <p class="para rdfs-comment"> Get the activation steepness for neuron number <em>neuron</em> in layer number <em>layer</em>, counting the input layer as layer 0. </p> <p class="para"> It is not possible to get activation steepness for the neurons in the input layer. </p> <p class="para"> The steepness of an activation function says something about how fast the activation function goes from the minimum to the maximum. A high value for the activation function will also give a more agressive training. </p> <p class="para"> When training neural networks where the output values should be at the extremes (usually 0 and 1, depending on the activation function), a steep activation function can be used (e.g. 1.0). </p> <p class="para"> The default activation steepness is 0.5. </p> </div> <div class="refsect1 parameters" id="refsect1-function.fann-get-activation-steepness-parameters"> <h3 class="title">Parameters</h3> <dl> <dt> <span class="term"><em><code class="parameter">ann</code></em></span> <dd> <p class="para">Neural network <span class="type"><a href="language.types.resource.html" class="type resource">resource</a></span>.</p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">layer</code></em></span> <dd> <p class="para"> Layer number </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">neuron</code></em></span> <dd> <p class="para"> Neuron number </p> </dd> </dt> </dl> </div> <div class="refsect1 returnvalues" id="refsect1-function.fann-get-activation-steepness-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> The activation steepness for the neuron or -1 if the neuron is not defined in the neural network, or <strong><code>FALSE</code></strong> on error. </p> </div> <div class="refsect1 seealso" id="refsect1-function.fann-get-activation-steepness-seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"> <span class="function"><a href="function.fann-set-activation-function.html" class="function" rel="rdfs-seeAlso">fann_set_activation_function()</a> - Sets the activation function for supplied neuron and layer</span></li> <li class="member"> <span class="function"><a href="function.fann-set-activation-steepness-layer.html" class="function" rel="rdfs-seeAlso">fann_set_activation_steepness_layer()</a> - Sets the activation steepness for all of the neurons in the supplied layer number</span></li> <li class="member"> <span class="function"><a href="function.fann-set-activation-steepness-hidden.html" class="function" rel="rdfs-seeAlso">fann_set_activation_steepness_hidden()</a> - Sets the steepness of the activation steepness for all neurons in the all hidden layers</span></li> <li class="member"> <span class="function"><a href="function.fann-set-activation-steepness-output.html" class="function" rel="rdfs-seeAlso">fann_set_activation_steepness_output()</a> - Sets the steepness of the activation steepness in the output layer</span></li> <li class="member"> <span class="function"><a href="function.fann-set-activation-steepness.html" class="function" rel="rdfs-seeAlso">fann_set_activation_steepness()</a> - Sets the activation steepness for supplied neuron and layer number</span></li> </ul> </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.fann-get-activation-function.html">fann_get_activation_function</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.fann-get-bias-array.html">fann_get_bias_array</a></div> <div class="up"><a href="ref.fann.html">Fann Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>