mark a value from matplotlib plot by changing the color backgorund and tracing lines

Question

Let's say I have these two arrays that I've plotted with matplotlib

Distance = [vlaue1; value2; value3...]

focus_measurement = [vlaue1; value2; value3...] [ enter image description here ]1

Using this code:

plt.plot(Distance, focus_measurement)
plt.xlabel('Distance (cm)'),plt.ylabel('Variance'), plt.title('Capteur')
plt.show()

Which gives this graph..

What I want to do now is to highlight the region of all the values greater than 1200 in the Variance and their equivalent in focus_measurement.

EDIT:

this is how you do it:

You add this line of code for the x axis:

plt.axvspan(180,300, facecolor="red", alpha=0.5)

Or this one for the y axis:

plt.axhspan(1200,1500, facecolor="red", alpha=0.5)

Which will give something like..

plt.plot(Distance, focus_measurement)
plt.xlabel('Distance (cm)'),plt.ylabel('Variance'), 
plt.title('Capteur')
plt.axvspan(180,300, facecolor="red", alpha=0.5)
plt.axhspan(1200,1500, facecolor="red", alpha=0.5)
plt.show()

Your desired outcome is not clear. Do you want to change the colour of the line for values that have a variance greater than 1200? — DavidG, Jul 03 '17 at 14:05
Do you want something like [this](https://stackoverflow.com/questions/8270981/in-a-matplotlib-plot-can-i-highlight-specific-x-value-ranges)? — GWW, Jul 03 '17 at 14:06
Exactly ! I want to change the colour background of all the valeus greater than 1200 in variance and their equivalence in distance — Mourad Over Flow, Jul 03 '17 at 14:06
@MouradOverFlow As you have figured out the answer it is better to post it as an answer then mark it as accepted rather than editing your question. — DavidG, Jul 03 '17 at 14:41
@DavidG Ok, I just posted an answer but I could not mark it as accepted, I don't not why. — Mourad Over Flow, Jul 03 '17 at 14:47
@MouradOverFlow You might have to wait a few minutes before you can accept it — DavidG, Jul 03 '17 at 14:49

score 0 · Answer 1 · answered Jul 03 '17 at 14:46

This is how you do it:

You add this line of code for the x axis:

plt.axvspan(180,300, facecolor="red", alpha=0.5)

Or this one for the y axis:

plt.axhspan(1200,1500, facecolor="red", alpha=0.5)

Which will give something like..

plt.plot(Distance, focus_measurement)
plt.xlabel('Distance (cm)'),plt.ylabel('Variance'), 
plt.title('Capteur')
plt.axvspan(180,300, facecolor="red", alpha=0.5)
plt.axhspan(1200,1500, facecolor="red", alpha=0.5)
plt.show()

mark a value from matplotlib plot by changing the color backgorund and tracing lines

1 Answers1