擅长:python、mysql、java
<p>使用无<code>for</code>-循环的快速单线解决方案是:</p>
<pre><code># initialization
qDCTReversed = np.arange(4*3*3).reshape((4,3,3))
# calculation
qDCTReversed = qDCTReversed.reshape((2,2,3,3)).transpose((0,2,1,3)).reshape((6,6))
</code></pre>
<p>或者对于<code>(400,8,8)</code>数组:</p>
^{pr2}$
<p><strong>速度比较:</strong></p>
<p><a href="https://stackoverflow.com/a/54593044/10960882">Mstaino's answer</a>:0.393毫秒</p>
<p><a href="https://stackoverflow.com/a/54593152/10960882">yatu's answer</a>:0.138毫秒</p>
<p>这个答案:0.016毫秒</p>