Vertical grid line for x=0

I am using horizontal gridlines for a plot.

ax = gca;
ax.XGrid = 'off';
ax.YGrid = 'on';

How can I add only one vertical line through x=0?

Answer 1

[Star Strider]

You can plot a vertical line anywhere by duplicating the x-coordinate and plotting it against ylim:

figure(1)
plot([0 0], ylim, '-r')
ax = gca;
ax.XGrid = 'off';
ax.YGrid = 'on';

Answer 2

[Image Analyst]

The best answer is to use YAxisLocation:

theta = linspace(-pi, pi, 800);
plot(theta, sin(theta), 'b-') % Plot something.
% Make axes go through origin instead of left and bottom sides of axes box.
ax = gca;
ax.XAxisLocation = 'origin'
ax.YAxisLocation = 'origin'

[Jan w]

Thanks! How can I put only an axis thorugh x=0 without having to move the whole YAxis? It should stay on the left side. I can't find any axis propertys: https://de.mathworks.com/help/matlab/ref/axes-properties.html Regards!

[Image Analyst]

I don't understand. Normally the Y axis is at the left hand side of the axes box. If you want it to remain there, then just don't set YAxisLocation. If you want to move it so that it crosses at the x=0 line, then set YAxisLocation = 'origin'.

The only way to not move the Y axis and have it still be on the left hand side, and to have that left hand side also be the x=0 location is to set xlim to be 0:

% Get current axes limits
xl = xlim();
% Set xl(1) = 0
xl(1) = 0;
% Update the x axes limits.
xlim(xl);

Is that what you want?

[Jan w]

Yes this works fine for me!

[Image Analyst]

You're welcome. Maybe you could "Vote" for the answer (under my logo).

Answer 3

[the cyclist]

line([0 0],[0 1],'Color','Black')

See line for details of setting the properties of the line.

[Brian Russell]

You simply need to write yline(0) or xline(0) for vertical and horizontal lines.

[Star Strider]

Note that xline and yline were introduced in R2018b, 1½ years after this was posted.