This is my code and when I run my grafic is this: enter image description here I don't know how to solve it. Just when I plot many values it happens. My file is this: https://drive.google.com/file/d/1gfljbTr82K5lLKRa7BVbs5JUmqtaZsp1/view?usp=sharing
I'm trying to plot errorbar of each value.
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
df = pd.read_csv('C:/Users/LENOVO/Downloads/PN_ART.txt', sep=" ", header=0)
#oxígeno
O3art = df.loc[:, 'O3']
eO3art = df.loc[:, 'eO3']
#Nitrógeno
N2art = df.loc[:, 'N2']
eN2art = df.loc[:, 'eN2']
#Hidrógeno
Halphart = df.loc[:, 'Halpha']
eHalphart = df.loc[:, 'eHalpha']
eHbetart = df.loc[:, 'eHbeta']
Y = np.log(O3art)
X = np.log(N2art/Halphart)
xe = eN2art + eHalphart
ye = eO3art + eHbetart
plt.plot(X, Y, 'go')
plt.errorbar(X, Y, xerr=xe, yerr=ye, color='k')
Matplotlib defaults to draw lines between succesive points. If you plot several points, that are not ordered along the x-axis, this will produce the strange zigzag lines you observe in your plot.
One solution would be to sort the data points by their x values. Another one would be to tell matplotlib to not draw the lines. This can be done by passing a
linestyle=''
to the plot commands. Usually if you happen to have this problem, the lines between the points don't have a meaning anyway, so it is also better to not draw them from a scientific point of view.
By the way you can (and should combine the plot() and errorbar() call into one errorbar() call e.g. like this
plt.errorbar(X, Y, xerr=xe, yerr=ye, marker='o', color='g', linestyle='', ecolor='k')
You can find the meaning of the arguments and additional options in the documentation of the errorbar() function.