<p>欢迎来到SO。。。要利用此站点,请将鼠标悬停在问题的标签<code>fft</code>上方。。。然后单击<code>View tag</code>。。。然后按<code>learn more</code>。。。在阅读完fft上的信息页面后,点击<code>Votes</code>查看这里投票率最高的帖子。。。这些问题/答案将使你进入球场</p>
<p>我强烈建议你掌握这里解释的细节<a href="https://www.youtube.com/watch?v=mkGsMWi_j4Q" rel="nofollow noreferrer">Discrete Fourier Transform - Simple Step by Step</a></p>
<p>傅里叶变换交互式指南<br/>
<a href="https://betterexplained.com/articles/an-interactive-guide-to-the-fourier-transform/" rel="nofollow noreferrer">https://betterexplained.com/articles/an-interactive-guide-to-the-fourier-transform/</a></p>
<p>对傅里叶变换和FFT的直观理解<br/>
<a href="https://www.youtube.com/watch?v=FjmwwDHT98c" rel="nofollow noreferrer">https://www.youtube.com/watch?v=FjmwwDHT98c</a></p>
<p>直观的离散傅里叶变换教程<br/>
<a href="http://practicalcryptography.com/miscellaneous/machine-learning/intuitive-guide-discrete-fourier-transform/" rel="nofollow noreferrer">http://practicalcryptography.com/miscellaneous/machine-learning/intuitive-guide-discrete-fourier-transform/</a></p>
<p><a href="https://stackoverflow.com/questions/7674877/how-to-get-frequency-from-fft-result">How to get frequency from fft result?</a></p>
<p>我可以继续从我的笔记中提到掘金,但我会留下这本优秀书籍的节选</p>
<pre><code>http://www.dspguide.com/ch10/6.htm
The Discrete Time Fourier Transform (DTFT) is the member of the Fourier transform family that operates on aperiodic,
discrete signals. The best way to understand the DTFT is how it relates to the DFT. To start, imagine that you
acquire an N sample signal, and want to find its frequency spectrum. By using the DFT, the signal can be
decomposed into sine and cosine waves, with frequencies equally spaced between zero and one-half of the
sampling rate. As discussed in the last chapter, padding the time domain signal with zeros makes the period
of the time domain longer, as well as making the spacing between samples in the frequency domain narrower.
As N approaches infinity, the time domain becomes aperiodic, and the frequency domain becomes a continuous signal.
This is the DTFT, the Fourier transform that relates an aperiodic, discrete signal, with a periodic,
continuous frequency spectrum
</code></pre>