Flux.jl/dev/models/regularisation/index.html

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<html lang="en"><head><meta charset="UTF-8"/><meta name="viewport" content="width=device-width, initial-scale=1.0"/><title>Regularisation · Flux</title><script>(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
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m = Dense(10, 5)
loss(x, y) = crossentropy(softmax(m(x)), y)</code></pre><p>We can regularise this by taking the (L2) norm of the parameters, <code>m.W</code> and <code>m.b</code>.</p><pre><code class="language-julia">using LinearAlgebra
penalty() = norm(m.W) + norm(m.b)
loss(x, y) = crossentropy(softmax(m(x)), y) + penalty()</code></pre><p>When working with layers, Flux provides the <code>params</code> function to grab all parameters at once. We can easily penalise everything with <code>sum(norm, params)</code>.</p><pre><code class="language-julia">julia&gt; params(m)
2-element Array{Any,1}:
param([0.355408 0.533092; … 0.430459 0.171498])
param([0.0, 0.0, 0.0, 0.0, 0.0])
julia&gt; sum(norm, params(m))
26.01749952921026</code></pre><p>Here&#39;s a larger example with a multi-layer perceptron.</p><pre><code class="language-julia">m = Chain(
Dense(28^2, 128, relu),
Dense(128, 32, relu),
Dense(32, 10), softmax)
loss(x, y) = crossentropy(m(x), y) + sum(norm, params(m))
loss(rand(28^2), rand(10))</code></pre><p>One can also easily add per-layer regularisation via the <code>activations</code> function:</p><pre><code class="language-julia">julia&gt; using Flux: activations
julia&gt; c = Chain(Dense(10, 5, σ), Dense(5, 2), softmax)
Chain(Dense(10, 5, σ), Dense(5, 2), softmax)
julia&gt; activations(c, rand(10))
3-element Array{Any,1}:
Float32[0.84682214, 0.6704139, 0.42177814, 0.257832, 0.36255655]
Float32[0.1501253, 0.073269576]
Float32[0.5192045, 0.48079553]
julia&gt; sum(norm, ans)
2.1166067f0</code></pre><article class="docstring"><header><a class="docstring-binding" id="Flux.activations" href="#Flux.activations"><code>Flux.activations</code></a><span class="docstring-category">Function</span></header><section><div><pre><code class="language-julia">activations(c::Chain, input)</code></pre><p>Calculate the forward results of each layers in Chain <code>c</code> with <code>input</code> as model input.</p></div><a class="docs-sourcelink" target="_blank" href="https://github.com/FluxML/Flux.jl/blob/ddd0f4e747347555894f71ae275ac3906fc87b9e/src/layers/basic.jl#L67-L71">source</a></section></article></article><nav class="docs-footer"><a class="docs-footer-prevpage" href="../recurrence/">« Recurrence</a><a class="docs-footer-nextpage" href="../layers/">Model Reference »</a></nav></div><div class="modal" id="documenter-settings"><div class="modal-background"></div><div class="modal-card"><header class="modal-card-head"><p class="modal-card-title">Settings</p><button class="delete"></button></header><section class="modal-card-body"><p><label class="label">Theme</label><div class="select"><select id="documenter-themepicker"><option value="documenter-light">documenter-light</option><option value="documenter-dark">documenter-dark</option></select></div></p><hr/><p>This document was generated with <a href="https://github.com/JuliaDocs/Documenter.jl">Documenter.jl</a> on <span class="colophon-date" title="Wednesday 27 May 2020 11:52">Wednesday 27 May 2020</span>. Using Julia version 1.3.1.</p></section><footer class="modal-card-foot"></footer></div></div></div></body></html>