How to plot a dashed line on seaborn lineplot?

Question

I'm simply trying to plot a dashed line using seaborn. This is the code I'm using and the output I'm getting

import seaborn as sns import numpy as np import matplotlib.pyplot as plt  n = 11 x = np.linspace(0,2,n) y = np.sin(2*np.pi*x)  sns.lineplot(x,y, linestyle='--') plt.show() 

What am I doing wrong? Thanks

Answer 1

It seems that linestyle= argument doesn't work with lineplot(), and the argument dashes= is a bit more complicated than it might seem.

A (relatively) simple way of doing it might be to get a list of the Line2D objects on the plot using ax.lines and then set the linestyle manually:

import seaborn as sns import numpy as np import matplotlib.pyplot as plt  n = 11 x = np.linspace(0,2,n) y = np.sin(2*np.pi*x)  ax = sns.lineplot(x,y)  # Might need to loop through the list if there are multiple lines on the plot ax.lines[0].set_linestyle("--")  plt.show() 

Update:

It appears the dashes argument applies only when plotting multiple lines (usually using a pandas dataframe). Dashes are specified the same as in matplotlib, a tuple of (segment, gap) lengths. Therefore, you need to pass a list of tuples.

n = 100 x = np.linspace(0,4,n) y1 = np.sin(2*np.pi*x) y2 = np.cos(2*np.pi*x)  df = pd.DataFrame(np.c_[y1, y2]) # modified @Elliots dataframe production  ax = sns.lineplot(data=df, dashes=[(2, 2), (2, 2)]) plt.show() 

Answer 2

In the current version of seaborn 0.11.1, your code works perfectly fine.

import seaborn as sns import numpy as np import matplotlib.pyplot as plt  n = 11 x = np.linspace(0,2,n) y = np.sin(2*np.pi*x)  sns.lineplot(x=x,y=y, linestyle='--') plt.show();