davrot/pytutorial
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Update README.md

Browse source 
Signed-off-by: David Rotermund <54365609+davrot@users.noreply.github.com>
This commit is contained in:
David Rotermund 2023-12-15 14:36:34 +01:00 committed by GitHub
parent f7f979f4da
commit 9a2f8e2906
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 25 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
numpy/fft/README.md
View file

@ -107,7 +107,7 @@ f = [0, 1, ..., (n-1)/2-1, (n-1)/2] / (d*n) if n is odd
> Unlike fftfreq (but like scipy.fftpack.rfftfreq) the Nyquist frequency component is considered to be positive.
### Comparison (cont.)
### Comparison (fftfreq)
The frequency axes:
@ -127,8 +127,8 @@ plt.xlabel("Frequency")
plt.title("FFT")
plt.show()
```
![image1](image1.png)
![image2](image2.png)
```python
plt.plot(rfft_freq, np.abs(rfft_result) ** 2)
@ -137,8 +137,30 @@ plt.xlabel("Frequency")
plt.title("rFFT")
plt.show()
```
![image2](image2.png)
![image1](image1.png)
### Comparison (ifft)
```python
plt.plot(t, x - np.real(np.fft.ifft(fft_result)))
plt.ylabel("Error x - ifft(fft(x))")
plt.xlabel("t")
plt.title("FFT")
plt.show()
```
![image3a](image3a.png)
```python
plt.plot(t, x - np.real(np.fft.irfft(rfft_result)))
plt.ylabel("Error x - irfft(rfft(x))")
plt.xlabel("t")
plt.title("rFFT")
plt.show()
```
![image4](image4.png)
## [Discrete Fourier Transform (numpy.fft)](https://numpy.org/doc/stable/reference/routines.fft.html#discrete-fourier-transform-numpy-fft)