# Questions tagged [signal-processing]

Digital signal processing of sound, video or other single or multidimensional data

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### Prevent running out of memory when doing SpectrogramArray?

I was using SpectrogramArray[Import@"myFile", 22050, 22050]to transfrom a piano mp3 file so that I can (probably?) generate a midi file from that mp3. The step size ...
185 views

### How to segment nuclei from a noisy image

(data can be downloaded from this link.) I am trying to segment and count nuclei in a noisy 3-D image stack and it is proving to be somewhat challenging. The strategy I could come up with requires ...
135 views

### Two-tone spectrogram

The default spectrogram command uses a single color and appears to just vary the saturation of the color to express intensity. So, for example, in the default implementation which looks like this: ...
968 views

### Detecting beat frequency using FFT

I wrote Mathematica FFT code that works for non-beat signals, eg. Sin[2*Pi/20*x] and more complicated but I can't obtain beat frequency of Sin[2*Pi*(10)*x] + Sin[2*Pi*(11)*x]. Also, what is general ...
181 views

### Plot cumulative distribution of a function

I want to calculate the probability $P(X\le-0.5)$. I have the probability density function $1/(\pi\sqrt{A^2 - x^2})$. $A$ is supposed to be the square root of noise power, $A = \sqrt{N_0}$, and so ...
120 views

859 views

### Why isn't LowPassFilter working for these parameters?

First I define a function, just a sum of a few sin waves at different angular frequencies: ...
252 views

### Identify a note in a song using Mathematica

I'm trying to figure out how to use Mathematica to identify a note from a song. The short .mp3 file found here or here contains a bass-note that I'd like to identify. I can find it through ...
186 views

### Filtering in frequency domain

I'm trying to modify a transfer function in the frequency domain by filtering it with a Butterworth filter. For example, let's say my transfer function is of the form : ...
464 views

### Applying a window over a list

The window functions state that they tread over lists, but when I try to do: HammingWindow/@list, I do not get the expected results. What is the best way to apply a window over an arbitrary length ...
866 views

### Finding outliers in 2D and 3D numerical data

I'm working on dataset which isn't normally distributed.which contains three dimensions like cost, discount and profit I'm trying to find outliers in all these dimensions. I used z score to find ...
264 views

### FindPeaks error “ Expecting an image or graphics instead of”

I'm running Mathematica 10.3.1.0 on windows 7 Professional Sp.1 when I try to use FindPeaks I keep getting the following error, even when trying the example in the ...
129 views

### Problem with Sin and ListPlot

In order to produce a smooth sine wave (Sin) and visualize it (ListPlot), I seem to need a very high sample rate (much higher than Nyquist). I want to know if this is a artifact of ListPlot or Sin ...