Pythonic way of setting a label in matplotlib

Question

I am iterating over many lists of gpx data to create a plot of cumulative training for 2016. To do so, I set up a loop as follows, where paces is a list of lists of smoothed pacing data from each gpx file and total_distances the associated distances computed from the coordinate data.

for i in range(0, len(paces)):

    if i == 0: 
        # need offset on paces from filtered data/NaN
        plt.plot(total_distances[i:i+1][0], 
                 paces[i:i+1][0][10:len(paces[i:i+1][0])+1], 
                 linewidth=.5, ls='-', color='#00FF00', label = 'all runs')
    else:
        plt.plot(total_distances[i:i+1][0], 
                 paces[i:i+1][0][10:len(paces[i:i+1][0])+1], 
                 linewidth=.5, ls='-', color='#00FF00')

If I do not use the above conditional, the label gets printed as many times as there are lists.

Any suggestions for a my pythonic way of doing this?

First things first, total_distances[i:i+1][0] is exactly total_distances[i] (same with paces). — DYZ
– DYZ, Commented Mar 30, 2017 at 22:44

ImportanceOfBeingErnest · Accepted Answer · 2017-03-30 22:55:46Z

1

I don't know what pythonic means (everyone seems to understand it differently), but here is a solution which might be easier to implement.

The idea is based on the fact that matplotlib ignores labels which start with an underscore (_). So adding i underscores in the loop to the label, leaves only the first label without an underscore. This is then the label being shown.

import matplotlib.pyplot as plt

x = range(39)
y = range(39)

for i in range(len(x)-1):
    plt.plot(x[i:i+2],y[i:i+2], lw=10, label="_"*i + "label")

plt.legend(borderpad=1.5)
plt.show()

answered Mar 30, 2017 at 22:55

ImportanceOfBeingErnest

342k61 gold badges737 silver badges771 bronze badges

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

1 Comment

horcle_buzz Over a year ago

Good question about the term pythononic. I guess easy to read, succinct, and efficient works for me! Worked like a charm. I've seen the _ usage before, especially for unpacking values from functions, but its usage, while pythonic(!), has always confused me.

DYZ · Accepted Answer · 2017-03-31 02:18:50Z

1

Not having the actual data, I cannot test my answer, but I believe you should use this code:

for i,(distance,pace) in enumerate(zip(total_distances, paces)):
    plt.plot(distance, pace[10:],
             linewidth=.5, ls='-', color='#00FF00', 
             label='' if i else 'all runs')

edited Mar 31, 2017 at 2:18

answered Mar 30, 2017 at 22:48

DYZ

57.3k10 gold badges73 silver badges101 bronze badges

3 Comments

horcle_buzz Over a year ago

Only issue with this is that distance and pace are of different lengths, so not sure how to adopt that with the slicing I need to do.

DYZ Over a year ago

They are of different length in your original code, too, aren't they?

horcle_buzz Over a year ago

Never mind. I did not see the slicing term on pace. My apologies!

Collectives™ on Stack Overflow

Pythonic way of setting a label in matplotlib

2 Answers 2

1 Comment

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related