python plot peaks on matplotlib.image.AxesImage object

Question

I have a an AxesImage object in Python from pylab. How do I plot points on top of the plot?

For example, I did imshow on a 2D array that I have, returning the AxesImage. Then I didn some peak finding and found (i, j) pairs which correspond to the peaks. Now all I have to do is overlay them on top of the image.

I think the scatter() function is normally how you plot something like this (?) but I couldn't get it to overlay.

Thanks!

lollercoaster · Accepted Answer · 2013-11-03 20:14:21Z

3

Solution was fairly simple, but wasn't aware you could use Axes objects like this:

import matplotlib.pyplot as plt

# detect peaks somehow
i, j = detect_peaks(array2d)

# plot
fig, ax = plt.subplots()
ax.imshow(array2d)
ax.scatter(i, j)
plt.show()

Probably very simple for most matplotlib experts, but took quite a bit of guesswork on my part.

answered Nov 3, 2013 at 20:14

lollercoaster

16.6k35 gold badges123 silver badges183 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

tacaswell Over a year ago

Please see stackoverflow.com/questions/14254379/…. This is what pyplot is doing underneath for you anyway.

Collectives™ on Stack Overflow

python plot peaks on matplotlib.image.AxesImage object

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related