Questions tagged [peak-detection]

Questions on peak detection algorithms and problems, including applications of the built-in FindPeaks, PeakDetect, MaxDetect and MinDetect.

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Fitting data to peaks visually with manipulate - how to compactly implement for many peaks

I am trying to create a visual aid for peak fitting. There should be a background profile and on top, I want to place peaks. So far, I am stuck with the following issue. For simplicity, I am using a ...
atapaka's user avatar
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3 votes
1 answer
141 views

FindPeaks in a 2d list and half values

FindPeaks is a nice little help. But it only works on 1D lists and tends to return half integer values for positions of the peaks which are ultimately very useless ...
atapaka's user avatar
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1 vote
1 answer
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Find local maximum

What instruction could I use to obtain the local maximum point of the red circle in the graph? I tried using the $FindMaximum$ instruction, but couldn't get the desired result. The curve generation ...
chen chen's user avatar
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4 votes
4 answers
198 views

Separating two peaks in a 2D array of data

I have a 2D array of count values and the data presents two peaks separated by a valley of low counts. I want to be able to separate each peak signal from the other so that I can analyse the ...
Richard's user avatar
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2 votes
0 answers
34 views

Generalise ImageLines to Image3DPlanes?

Context I am interested in detecting (multiple) planes in a cube. Test case Let me first define a test case: ...
chris's user avatar
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56 views

Plot the peak frequency of a ShortTimeFourirer Transformation and convert bin # to frequency

I did the ShortTimeFourier(stf) Transformation of the following signal. And got the results as shown in this Spectrogram. Then I wanted to find the peak frequency of this each turn using PeakDetect ...
user85978's user avatar
1 vote
2 answers
189 views

FindPeaks of elevation data

I've been reading many posts about how to use FindPeaks. I am working with some GPX data and was looking to plot an elevation profile with points at the peaks and troughs, potentially with those ...
Tom De Vries's user avatar
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2 votes
1 answer
135 views

Functions can graph but can't solve for partial derivatives

First I got a function g[xo,yo] by solving a system of partial differential equations ...
shrocat's user avatar
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0 votes
1 answer
114 views

Selecting data around peak position

I'm trying to write code that imports experimental data, finds peaks in it and cuts data around specific peak for further analysis (Fourier transform & model fitting of spectra). Currently, I'm ...
Justinas J.'s user avatar
1 vote
1 answer
83 views

What is the best way to detect constant or periodic amplitude of the spectrogram?

Suppose I get interpolating function in the solution of the complicated differential system. I plot a solution for various input values that control the outcome of the solution. Some give exponential ...
Aschoolar's user avatar
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1 vote
1 answer
96 views

Fitting data by linear combination of distribution [closed]

I have data ...
Nancy's user avatar
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6 votes
2 answers
511 views

Inflection point coordinates of peaks in data

Using the following data, which I have used before in other posts (the y-axis is heat flow (mW) and x-axis is Temperature in °C (not time)): ...
John's user avatar
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6 votes
1 answer
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Find onset and peak temperatures

If I have the following data (which is temperature in the x-axis and heat flow in the y-axis): Import["https://pastebin.com/raw/SMKZUtbQ", "Package"] which ...
John's user avatar
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8 votes
2 answers
376 views

Remove a specific element of a TimeSeries?

If I have a TimeSeries, how do I remove an element if that element is another TimeSeries? Let's say I have: ...
Brecky Morris's user avatar
2 votes
2 answers
120 views

Track a moving peak on a periodic ListAnimate plot

I have a ListAnimate plot and I want to track the position of the peak as it moves. Is there any way to do this which takes into account the fact that the peak of the wave moves past the window of ...
James's user avatar
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1 vote
0 answers
114 views

How to perform a 2D-multi-peak fitting?

I am wondering how to decompose the data[x,y] into several elliptic-shaped functions, i.e. $f[x,y]=\frac{H}{(1+(\frac{x-x1}{a1})^2+(\frac{y-y1}{b1})^2)^{3/2}}$. I could follow in 1D case, ...
Ui-Jin Kwon's user avatar
1 vote
1 answer
156 views

Sort and extract values in a nested list

I want to sort the following nested list of peak points by the y values while keeping the dimensions consistent. I then want to extract the x value of the largest and second largest y values (if the ...
James's user avatar
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2 votes
0 answers
157 views

Simultaneous Peak and Background Fit

I'm not sure if this is the proper way to do this, but I have a question related to another open question of mine. In this post, I'm looking at analyzing some quantum dot UV-Vis absorbance spectra (...
BesselFunct's user avatar
1 vote
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Quantum Dot Absorbance Data Peakfinding

I work in a lab making quantum dots, and was recently tasked with finding a way to extract some figures of merit from old data in an automated way. In particular, I'm looking to extract the peak ...
BesselFunct's user avatar
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0 answers
84 views

Fitting CauchyDistribution to data list to determine peak

I have a list of data in the form like this {{-3,12},{-3.01,13.4},{-3.04,13.6},...} where the x value is time and the y value is current. FindPeak gives me peaks for everydata point i have and ...
Eis Kekks's user avatar
2 votes
1 answer
175 views

PeakDetect Function Behavior and Parameters

I am currently using PeakDetect for a project, but I'm not sure how the sharpness parameter works. I can qualitatively tell what it's doing, but is there a more analytical/mathematical way to define ...
Pran's user avatar
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1 vote
1 answer
119 views

Removing Extra Points When Finding an Audio Envelope

I am trying to reproduce Camtasia's way of displaying audio signals which is a strictly positive envelope of the audio signal and very easy for me to identify some sounds visually. These are displays ...
Gene's user avatar
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5 votes
0 answers
160 views

Optimize Use of PeakDetect in Mathematica

I am quite new to Mathematica and I am looking for some advice in order to improve and optimize my code. Here is what I am trying to do: Open a stream Read the stream line by line and store it in "...
etotheix's user avatar
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2 votes
3 answers
452 views

Finding minimum from ListPlot

I have Table with 10000 elements in it and I plot a graphic using ListPlot. I need find minimum in graph. Here is a .txt file with data. I tried to use ...
John's user avatar
  • 573
0 votes
3 answers
353 views

Find peaks in data set and correlate variables [closed]

I have a data set composed of a X variable (col 1) and two Y variables. Y1 shows roughly 40 peaks while Y2 is a linear function. Is it possible to find the approximated 40 Y2 values for which Y1 is a ...
Rodrigo's user avatar
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2 votes
2 answers
310 views

How to find second,third,etc maximum peak of list

I need to find all values of peaks. I have Table with 10000 elements in it and I plot a graphic using ListPlot. Then I tried to ...
John's user avatar
  • 573
5 votes
2 answers
92 views

Find the base vectors of a point set

I have a list of coordinates that fits into a 2D periodic lattice, with some error ( $\vec{R}=n\vec{i}+m\vec{j}+\vec{\varepsilon}$). Is there a way to find the base vectors of the lattice? I guess the ...
arax's user avatar
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5 votes
3 answers
745 views

Efficient way to detect peak value changes in a list

ListPlot[list, Joined -> True, PlotRange -> Full] I would like a simple method to get the positions within the list where the values deviate a lot from ...
james's user avatar
  • 3,023
6 votes
3 answers
942 views

Multi-peak fitting for peak position

I have a {x,f} data-set featuring multiple peaks. The peaks evolve with a second variable y. I would like to fit the multiple ...
sole's user avatar
  • 81
6 votes
1 answer
524 views

Find centroids and average intensities of regions in an image

The image below shows an approximately triangular array of bright spots. The intensity falls off towards the edges (Gaussian decay). There are some defects (the elongated smudge and the sharper ...
Tom's user avatar
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0 votes
1 answer
385 views

Finding peaks/maxima while extracting the range of x-values

I have read similar questions about finding peaks on the web (Finding peaks of data) as well as the FindPeaks function but I'm struggling to put them into proper context for my case. I am still a new ...
kowalski's user avatar
  • 375
1 vote
3 answers
409 views

Multi-peak fitting

I am starting, and still learning with Mathematica. I really wonder how to solve my problem : I have a broad peak composed by two peaks actually, and I would like to separate them. Data come from an ...
L. Chassou's user avatar
3 votes
2 answers
367 views

Find peak decibel level (or some measure of peak loudness) from audio sample

So a shotgun range opened near my house and I've been tasked by the HOA to do some nuisance analysis. I've got a quick sample of audio and want to find the peak noise levels at the places where the ...
Matt Stein's user avatar
4 votes
2 answers
1k views

Find positions and values of peaks

FindPeaks only works on a single dimension list and returns the position as an index, however, there are cases when it can return non-integer value as a position, ...
atapaka's user avatar
  • 3,874
5 votes
0 answers
622 views

Detect and measure smooth peaks in a 2D image

I have multiple grayscale images where I want to identify elevations: I have to find the convex hull that encloses the base of each hill. An example image: The images are already normalized, ...
István Zachar's user avatar
1 vote
1 answer
63 views

Plot terminating early

I have a function K3T[2][2 r0 l, g2, z, c, T, p] that is acting weird when evaluated for different p: ...
Janosh's user avatar
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0 votes
0 answers
157 views

How to draw local trend lines and divergence lines?

Here are two lists as lstClose and lstCCI, the lstCCI is computed from ...
Jerry's user avatar
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2 votes
1 answer
728 views

Mysterious "not a consistent list of real values" error from FindPeaks

I am working with temporal data objects and experimenting with FindPeaks. I find that the function sometimes fails with the error FindPeaks::arg: The argument ...
Michael Stern's user avatar
0 votes
1 answer
402 views

Plotting a general ZigZag curve with possible threshold value

I want to use zigzag curve to describe the trend of simple data. here is a list as ...
Jerry's user avatar
  • 2,459
4 votes
0 answers
200 views

FindPeaks confused by initial zeros?

I think that there is something wrong with the FindPeaks algorithm. It seems to get confused when the data starts with some zeros. Here is works well: ...
Gustavo Delfino's user avatar
4 votes
2 answers
959 views

Integrating curve peaks

I have curve with a set of peaks (black line in the figure below) and I have to calculate the area of each peak. At the end of each peak there is a short linear region. So to calculate peaks' area ...
Филипп Цветков's user avatar
3 votes
1 answer
804 views

Filtering Background with resonance or Peaks

I have some data, the blue curve which I want to filter out the background to get a flat signal with dips(Idea is to divide signal (except the dips) by the background). The orange curve is my best ...
el psy Congroo's user avatar
5 votes
2 answers
1k views

Finding very weak peaks

I measured 1d particle oscillations. The particle is oscillating with a certain frequency, whereby its motion is disturbed. Now I would like to to find all peaks of the particles trajectory. One ...
mrz's user avatar
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8 votes
1 answer
753 views

Finding peaks of curve with small values

I have 2d data of which I want to find the peaks. data << "http://pastebin.com/raw/EQFz1KFn"; peaks = FindPeaks[data[[All, 2]], 0, 0, -Infinity] // N The ...
mrz's user avatar
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1 vote
1 answer
238 views

Extracting Features from a List

Data: https://drive.google.com/file/d/0B7G3oUuZG1TwYWhMVUhSQzNwTEk/view?usp=sharing Here I have 20 datasets collected from custom built EMG sensors monitoring a users face. I am particularly just ...
William John-Pierre Duhe's user avatar
3 votes
3 answers
987 views

Finding the width of a bell-shaped curve at half its peak value dynamically in a Manipulate

Kind of new to Mathematica. I am plotting a function that produces a bell-shaped curve in Mathematica within a Manipulate so that I can change its parameters easily....
anonymous's user avatar
  • 433
1 vote
2 answers
908 views

How do I extract peak frequencies? [closed]

Suppose I have large text file filled with numerical data. Then I do Fourier operation with this file and plot the result: ...
newt's user avatar
  • 337
14 votes
2 answers
1k views

How to detect loops in a vector field?

Given a vector field and I'd like to detect if there are streamlines in closed patterns. For example, if the input is a vector field like this: ...
M.R.'s user avatar
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2 votes
1 answer
415 views

How to find the local minimum points in the multi-dimensional numerical data?

I am trying to get some local minima of an n-dimensional function (which only has numerical form). For two-dimensional function data, we can find the local minimum points from the contour plot easily. ...
Orders's user avatar
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2 votes
1 answer
249 views

Still more problems with Fitting, please help

I'm in a little over my head here and I'm fully aware of it, so I'm hoping for some help. I've been assigned to a project where I am given data: http://www.pastebin.ca/3061136 (Example Data) I then ...
RNPF's user avatar
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