# Tag Info

## Hot answers tagged python

23 votes

### When concatenating sine waves, how do I phase shift in order to prevent "pops" caused by sudden jumps in amplitude?

A simple solution is to implement the waveform in phase versus time instead of frequency versus time which can then facilitate phase continuous transitions. Frequency is the time derivative of phase, ...
• 37.7k
10 votes

### Signal processing in Python vs C++ (band-pass filter)

Not really an answer but too long for a comment. Standard software development and debug techniques should solve this Don't use code on real data before it has passed all unit tests First write the ...
• 32.8k
8 votes
Accepted

### SOS-matrices' order does not correspond to given parameter when designing bandpass with scipy.signal.butter

Your expectations are reasonable. However, the definition of order in the design routine is confusing. It's the same in Matlab/Octave. For lowpass or highpass ...
• 80.4k
7 votes
Accepted

### Kalman Filter State Covariance Matrix for Non Constant Process Noise Matrix in PyKalman

For classic Kalman Filter, where ${Q}_{k} = Q$ and ${R}_{k} = R$, namely the process noise covariance and the measurement noise covariance (I'm using Wikipedia - Kalman Filter notations) the ...
• 41.4k
7 votes
Accepted

### How Are MATLAB's cpsd() and SciPy's csd() Related?

Both scipy.signal.csd() and MATLAB's cpsd() use Welch's method. But their default parameters are different: Window: On MATLAB ...
• 41.4k
7 votes
Accepted

### Can the deconvolution Wiener filter reduce noise without having a blurred image?

For Salt and Pepper noise on medical or real world images using the Wiener Filter isn't recommended. The Wiener filter basically takes advantage only on the knowledge from the spectrum of the data. ...
• 41.4k
6 votes

### Python vs Matlab? Which one better for image processing?

I have spent the first 20 years of my career working extensively in MATLAB for signal processing applications. Six years ago I gravitated over to Python out of curiosity and it has since completely ...
• 37.7k
6 votes
Accepted

### Which Programming Language Should Be Used for Deep Learning (Deep Neural Network [DNN])?

The language choice depends on many factors. For instance, are you after developing low level features of DNN or using existing building blocks? Most advanced and popular Deep Neural Networks (DNN) ...
• 41.4k
5 votes
Accepted

• 32.8k
3 votes

### Finding the mode of propagation of a progressive wave and the velocity of that mode

In your case the wave number $k = 2\pi f/c=2\pi$, $k_x$ and $k_y$ should satisfy $$k^2 = k_x^2+k_y^2$$ which means they are not always real. But the direction of propagation of wave is easy to ...
• 2,628
3 votes

### Finding the mode of propagation of a progressive wave and the velocity of that mode

As already commented so far, for the linear wave equation to be satisfied in any number of dimensions the condition (here shown for three dimensions) $$k^{2} = k_{x}^{2} + k_{y}^{2} + k_{z}^{2}$$ ...
• 742
3 votes
Accepted

### Performing STFT after Butterworth Filter Seems Lower in Resolution

Color norm is the problem. By default, colors are mapped from im.min() to im.max(), so a single high-valued pixel will make the ...
• 5,377
3 votes

### Can the deconvolution Wiener filter reduce noise without having a blurred image?

Can a deconvolution Wiener filter reduce noise without blurring? Maybe. Maybe not. There is not one Wiener filter. Any concrete "Wiener filter" is a plain old filter that has been ...
• 8,666
3 votes

### When concatenating sine waves, how do I phase shift in order to prevent "pops" caused by sudden jumps in amplitude?

Use phase from the start, and do not just multiply by time t - this is vital For each sine wave, use a variable to hold the current phase. Then for each time step, multiply ...
• 311
3 votes

### What is the relationship among digital filter cutoff frequency, signal frequency and filter settling time?

(1) Filter settles slower if the ratio between signal frequency and filter cutoff frequency is smaller; (2) Filter settles slower if bandwidth of a band-pass filter is narrower: Correct in the sense ...
• 32.8k
2 votes
Accepted

### Interpolation from discrete time fourier transform in python

If your signal is periodic you can simply interpolate by padding zeros in the frequency domain. This is equivalent to infinite circular sinc() interpolation and ...
• 32.8k
2 votes

### Python vs Matlab? Which one better for image processing?

MATLAB's Image Processing toolbox is much richer than what you'd find on Python except OpenCV. OpenCV on Python doesn't feel natural yet still give you access to basically the largest library of image ...
• 349

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