How to define the peaks of a graph?

[joziask]

Here is the graph of which I would like to determine the peaks. When I’ve done that, I would like to connect the dots. However I have no clue how to actually make this happen. Below is the code I currently have, but it sets markers all across my line graph from the first picture. Please help!

[AIMPED]

Hi @joziask, I think I answered a similar question some time ago:

In scatter plot, create line connecting lowest y values over x

Hi @nogons welcome to the forums. Yes, you can do that. You just have to add a trace with the minimum values: import numpy as np import plotly.express as px # create data arr = np.random.randint(0, 2000, size=(10, 30)) # create base figure fig = px.scatter(arr) # formatting fig.update_traces( showlegend=False, marker_color='black', marker_size=8 ) # add trace with minimum values fig.add_scatter( x=[*range(10)], y=np.min(arr, axis=1), name='minumum', marke…

How do you define a peak, that would be the question.

Scipy has actually module for peak detection:
https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.find_peaks.html

A first search on stackoverflow shows some example usages:

Counting Peaks in a Time Series

[joziask]

Unfortunately it does not work yet. I’ve created an array of the values in my graph, but I get the following error.

[AIMPED]

Hi @joziask , what’s the shape of value_array? Try axis=0.