Fourier transform means that functions that meet certain conditions can be expressed as trigonometric functions (sine and/or cosine functions) or linear combinations of their integrals. In different research fields, Fourier transform has many different variants, such as continuous Fourier transform and discrete Fourier transform. Firstly, Fourier analysis is proposed as a tool for thermal process analysis.
There are several Chinese translations of Fourier transform or Transformée de Fourier, and the common ones are Fourier transform, Fourier transform, Fourier transform, Fourier transform and so on.
Fourier transform is a method to analyze signals. It can analyze the components of the signal, and can also use these components to synthesize the signal. Many waveforms can be used as signal components, such as sine wave, square wave, sawtooth wave and so on. Fourier transform uses sine waves as signal components.
Fourier is the name of a French mathematician and physicist. His original English name is jean baptiste joseph fourier (1768- 1830). Fourier is very interested in heat transfer. 1807, he published a paper in the French society of science, describing the temperature distribution with sine curve.
There was a controversial decision in the paper at that time: any continuous periodic signal can be composed of a set of appropriate sinusoidal curves. At that time, there were two famous mathematicians in history, namely Joseph Louis Lagrange (1736- 18 13) and Laplacian (1749- 1827).
When Laplace and other reviewers voted to publish this paper, Lagrange firmly opposed it. For the next six years, Lagrange insisted that Fourier's method could not represent angular signals, such as discontinuous slopes in square waves.
The French scientific society succumbed to Lagrange's prestige and rejected Fourier's work. Fortunately, Fourier has other things to do. He took part in the political movement. After Napoleon's expedition to Egypt, the French Revolution was put to the guillotine, and he has been escaping. This paper was not published until 15 after the death of Lagrange.