matlab - set tick label at origin

2
votes

In generating plots with Matlab, when both the x and y minimum are zero, I prefer to have only one zero marking the origin rather than denoting it on both axes.

Matlab defaults to the latter, like so

figure with 'double origin'

Whereas I want something more like this

figure with 'single origin'

This can be done manually, but I'm trying to automate the process. Removing the x and y tick labels for 0 are obviously easy enough. However, I can't seem to access any handle for the position of the axis tick labels to properly position a text box for the 'new origin'. It seems the tick label offsets from the x and y axes may be somewhat constant in a given figure (in physical units, not normalized units), but I don't know if this is a standard across all figures or axes.

Any ideas?

I'm running Matlab 2014b.

2
matlabplotmatlab-figure

2 Answers

0
votes

Here's a simple way to do that:

% somthing to plot:
x = 0:0.1:2*pi;
y = abs(sin(x)+cos(x));
plot(x,y)

% get the handle for the current axes:
ax = gca;
% get the position of the zero tick on y-axis:
zeroYtick = ax.YAxis.TickValues==0;
% remove it (tick and lable)
ax.YAxis.TickValues(zeroYtick) = [];

The result:

zero tick

If you want the 0 to be offset a little to the left, so it will be at the corner of the plot, you can use annotation:

% get the position of the zero tick on x-axis:
zeroXtick = ax.XAxis.TickValues==0;
% remove it (tick and lable)
ax.XAxis.TickValues(zeroXtick) = [];
% place a new zero at the origin:
dim = [0.1 0.01 0.1 0.1];
annotation('textbox',dim,'String','0',...
    'FitBoxToText','on','LineStyle','none')

And you will get:

zero tick 2

The advantage in annotation is that the origin always placed relative to the corner of the axes, and you don't need to know the values of the axes ticks to properly offset it.

EDIT:

For pre 2016a version you can use the following (I wrote it a little more compact):

ax = gca;
% remove the zero tick on y-axis (tick and lable):
ax.YTick(ax.YTick==0) = [];
% remove the zero tick on x-axis (tick and lable):
ax.XTick(ax.XTick==0) = [];
% place a new zero at the origin:
dim = [0.1 0.01 0.1 0.1];
annotation('textbox',dim,'String','0',...
    'FitBoxToText','on','LineStyle','none')

EDIT 2:

Another option to keep the 0 in place is to stick it to the axes. this is done by replacing the Parent with the axes handle. First, we need a handle to the annotation (continuing from the last edit):

t = annotation('textbox',dim,'String','0',...
    'FitBoxToText','on','LineStyle','none');

then we switch the Parent and set the new position:

t.Parent = ax;
t.Position(1:2) = -[0.2 0.1];

and finally, we super-glue it by converting the Units to pixels:

t.Units = 'Pixels';
0
votes

The following will exclude the first tick on yaxis without shifting the graph at all. You can ensure that the correct item is being removed by setting the axis limits, ylim([0,upper_limit]) prior to removing the first one, or manually setting your yTicks, set(h,'yTick',my_ticks). Note that yTick changes the position of the ticks, while yTickLabel will change the text appearing at each position of yTick

h = plot([0,1],[0,1]);
yTicks = get(h,'yTick');
set(h,'yTick',yTick(2:end));