drummyfish/less_retarded_wiki
5
1
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Update

Browse source
This commit is contained in:
Miloslav Ciz 2024-03-08 16:56:58 +01:00
parent f920115b91
commit 75f99e7b81
69 changed files with 2008 additions and 1791 deletions
Download patch file Download diff file Expand all files Collapse all files

4
fourier_transform.md
View file

@ -41,7 +41,7 @@ IDFT[k] = 1/N * /__ x[n] * e^(2 * i * pi * k * n / N)
n = 0
```
OK, this is usually where every noob ragequits if he hasn't already because of all the [pi](pi.md)s and [e](e.md)s and just generally ununderstable mess of weird symbols etc. What the heck does this all mean? As said above, it's doing nothing else than [dot product](dot_product.md) or vectors really: one vector is the input signal and the other vectors are the individual frequencies (sine waves) we are trying to discover in the signal -- this looks so complicated because here we are actually viewing the general version for a possible [complex](complex_number.md) input signal, the *e to something* part is actually the above mentioned complex exponential, it is the exponential way of writing a complex number (see e.g. [Euler's identity](eulers_indentity.md)). Anyway, considering only real input signal, we can simplify this to a more programmer friendly form:
OK, this is usually where every noob ragequits if he hasn't already because of all the [pi](pi.md)s and [e](e.md)s and just generally ununderstable mess of weird symbols etc. What the heck does this all mean? As said above, it's doing nothing else than [dot product](dot_product.md) or vectors really: one vector is the input signal and the other vectors are the individual frequencies (sine waves) we are trying to discover in the signal -- this looks so complicated because here we are actually viewing the general version for a possible [complex](complex_number.md) input signal, the *e to something* part is actually the above mentioned complex exponential, it is the exponential way of writing a complex number (see e.g. [Euler's identity](eulers_identity.md)). Anyway, considering only real input signal, we can simplify this to a more programmer friendly form:
```
DFT:
@ -206,4 +206,4 @@ int main(void)
}
```
TODO: pictures, 2D version
TODO: pictures, 2D version