plot vlines with matplotlib.pyplot

Question

I'm trying to plot vertical lines in a log plot

xv1 = 10

plt.semilogy(t,P,'b')
plt.semilogy(t,Pb,'r')
plt.vlines(xv1,-1,1,color='k',linestyles='solid')
plt.xlabel('Time [s]')
plt.ylabel('P [Pa]')
plt.grid()
plt.show()

The vlines does not show up in the plot (it does for plt.plot)

Any ideas? Thanks!

Can you also include some (fake?) data with your code? It is hard to test if don't know what you inputs are. — tacaswell
– tacaswell, Commented May 6, 2013 at 15:21
Why do you use a semi-lograithmic plot (which cannot contain values y=0) and still want your vertical line to extend from -1 to 1? If you want to have a line extending across the entire figure, you should probably use axvline. — David Zwicker
– David Zwicker, Commented May 6, 2013 at 15:30
@DavidZwicker Completely missed the semi-log.... What version of mpl are you using? There has been some tweaking in how clipping of undefined values is handled in log plots. — tacaswell
– tacaswell, Commented May 6, 2013 at 16:47
As an additional remark: if you do wish to plot data that is also negative on a log axis use ax.set_yscale("symlog"). — Greg
– Greg, Commented May 6, 2013 at 22:08

fraxel · Accepted Answer · 2015-01-12 15:47:17Z

29

For plotting vertical lines that span the entire plot range, you may use axvline. Your code could then read

xv1 = 10

plt.semilogy(t, P, 'b')
plt.semilogy(t, Pb, 'r')
plt.axvline(xv1, color='k', linestyle='solid')
plt.xlabel('Time [s]')
plt.ylabel('P [Pa]')
plt.grid()
plt.show()

edited Jan 12, 2015 at 15:47

fraxel

35.4k11 gold badges101 silver badges104 bronze badges

answered May 7, 2013 at 7:30

David Zwicker

24.4k8 gold badges68 silver badges80 bronze badges

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

Collectives™ on Stack Overflow

plot vlines with matplotlib.pyplot

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related