Most Popular
1500 questions
11
votes
5 answers
How should a moving average handle missing data points?
I'm writing a program that averages the user's weight across different days. I'm planning to use a 5-point moving-average (current day, two before and two after). Sometimes, a data point is missing for 1-2 days. How are these cases usually…
Anna
- 357
- 2
- 3
- 9
11
votes
1 answer
How can I automatically classify peaks of signals measured at different positions?
I have microphones measuring sound over time at many different positions in space.
The sounds being recorded all originate from the same position in space but due to the different paths from the source point to each microphone; the signal will be…
Andy
- 1,783
- 2
- 17
- 27
11
votes
2 answers
What is the definition of a "complementary filter"?
I'm writing my MSE thesis report on an inertial navigation problem I've been working on. In my work, I use a complementary filter to track the orientation of a device. Now, since my fellow students are likely not familiar with complementary filters…
Svj0hn
- 219
- 1
- 2
- 5
11
votes
4 answers
Audio output quality
When a digital device (PC, portable media player, etc.) plays a digital audio file (ogg, mp3, flac, etc.) the audio signal output is always the same, regardless of the device type/brand, am I right? Thus the sound quality should not differ. For…
sterz
- 213
- 1
- 6
11
votes
4 answers
Calculate and interpret the instantaneous frequency
I'm new to the principle of calculating the instantaneous frequency, and came up with a lot of questions on it. You find them all in a bullet-point list at the end of this text. The text might be a little long, excuse me for that, but I really tried…
muuh
- 243
- 1
- 2
- 6
11
votes
2 answers
How to do prediction using frequency domain data?
Both linear regression and Kalman filtering can be used to estimate and then predict from a time domain sequence of data (given some assumptions about the model behind the data).
What methods, if any, might be applicable to do prediction using…
hotpaw2
- 35,346
- 9
- 47
- 90
11
votes
3 answers
Shift a signal by fraction of a sample
I have a signal with a sample time of 0.5 micro seconds and I would like to shift this signal by a fraction of the sample time, say by 3 nano seconds.
I have read a few online resources about fractional delay filtering and about using the FFT and…
smyslov
- 349
- 5
- 17
11
votes
2 answers
What is the difference between $X(j\omega)$ and $X(\omega)$ notation?
What is the difference between $X(j\omega)$ and $X(\omega)$ notation?
What is the meaning of $j\omega$?
Does it represent frequency, and if yes, what is the meaning of an imaginary frequency?
verdery
- 259
- 3
- 9
11
votes
3 answers
Why are sidebands generated in AM and FM?
When the signal is modulated onto the carrier in the electromagnetic spectrum,
that signal occupies the small portion of the spectrum surrounding the carrier frequency. It also cause sidebands to be generated at frequencies above and below the…
Sufiyan Ghori
- 2,175
- 11
- 34
- 50
11
votes
2 answers
On the de-noising of time-frequency images
I am wondering what techniques might be available for 'de-noising' the following example time-frequency image that was created using Welch's method. The following plot was created from a robotic sensor. (This is NOT a color image - it is a greyscale…
Spacey
- 9,817
- 8
- 43
- 79
11
votes
2 answers
What is difference between OFDM and GFDM?
I am trying to understand the difference(s) between OFDM (Orthogonal Frequency Division Multiplexing) and GFDM (Generalized Frequency Division Multiplexing) which are used as a multicarrier modulation techniques in wireless communication. As far as…
tuner
- 635
- 1
- 9
- 17
11
votes
4 answers
What are poles and zeros?
The concept of poles and zeros in filters was introduced to me during our lab (our lab isn't sync with our lecture) through the pole-zero plot generation of filters in MATLAB. I didn't get its importance until it was mentioned in our lecture that…
ellekaie
- 231
- 1
- 2
- 5
11
votes
2 answers
Wavelet Transform
I want to perform 2D haar discrete wavelet transform and inverse DWT on an image.Will you please explain 2D haar discrete wavelet transform and inverse DWT in a simple language and an algorithm using which I can write the code for 2D haar dwt?The…
user1320483
- 119
- 1
- 4
11
votes
1 answer
Recover curves from noisy collection of points
Background: I'm trying to make a system that tracks a number of bubbles in a video
I'm implementing the bubble detection in the single image case using the Circular Hough Transform. Due to occlusion, blur and other factors, this detection will never…
Alex
- 113
- 3
11
votes
3 answers
Image analysis - fiber recognition
I am completely new to image analysis. Do you know how to binarize this image in such a way to get the fibers only?
A step by step procedure would be awesome, but any hint is appreciated as well. I can use Matlab, .NET and I am open to any other…
Oldrich Svec
- 213
- 1
- 3