>
<span><span class="va">mnist_train</span><span class="op">$</span><span class="va">x</span> <span class="op">=</span> <span class="va">tf</span><span class="op">$</span><span class="va">dtypes</span><span class="op">$</span><span class="fu">cast</span><span class="op">(</span><span class="va">mnist_train</span><span class="op">$</span><span class="va">x</span>, <span class="st">'float32'</span><span class="op">)</span> <span class="op">/</span> <span class="fl">255.</span></span>
<span><span class="va">mn