I am stuck when I have generated a set of data and tried to color the plot line in python.
For example I would like to change the line color from blue to black here.
This is what I have and returns is the set of data that I got from pandas.
ax=plt.gca()
ax.set_axis_bgcolor('#cccccc')
returns.plot()
This question is related to
python
matplotlib
The answer is
The usual way to set the line color in matplotlib is to specify it in the plot command. This can either be done by a string after the data, e.g. "r-" for a red line, or by explicitely stating the color argument.
import matplotlib.pyplot as plt
plt.plot([1,2,3], [2,3,1], "r-") # red line
plt.plot([1,2,3], [5,5,3], color="blue") # blue line
plt.show()
See also the plot command's documentation.
In case you already have a line with a certain color, you can change that with the lines2D.set_color() method.
line, = plt.plot([1,2,3], [4,5,3], color="blue")
line.set_color("black")
Setting the color of a line in a pandas plot is also best done at the point of creating the plot:
import matplotlib.pyplot as plt
import pandas as pd
df = pd.DataFrame({ "x" : [1,2,3,5], "y" : [3,5,2,6]})
df.plot("x", "y", color="r") #plot red line
plt.show()
If you want to change this color later on, you can do so by
plt.gca().get_lines()[0].set_color("black")
This will get you the first (possibly the only) line of the current active axes.
In case you have more axes in the plot, you could loop through them
for ax in plt.gcf().axes:
ax.get_lines()[0].set_color("black")
and if you have more lines you can loop over them as well.
If you get the object after creation (for instance after "seasonal_decompose"), you can always access and edit the properties of the plot; for instance, changing the color of the first subplot from blue to black:
plt.axes[0].get_lines()[0].set_color('black')
Source: Stackoverflow.com