All this method is based on Fourier transform.

这个方法是以富氏变换为基础。

Fourier transform looks at the whole signal at once, Strang says.

“傅里叶变换一次性地考察整个信号，”Strang说。

One is the fast Fourier transform (FFT) accelerated algorithm.

一种是快速傅立叶变换(FFT)加速算法。

“Fourier transform looks at the whole signal at once, ” Strang says.

“傅里叶变换一次性地考察整个信号，”Strang说。

Fast Fourier Transform (FFT) is an effective method to detect harmonic.

快速付立叶变换(FFT)是对谐波进行检测的有效方法。