How can I move the Xlabel without moving the X-Axis?

I am having a hard time positioning the XLabel outside the plot and centered without moving the X-axis which is in the origin, here's my code:

x = [0:0.001:0.083];
y = (169.7056)*sin((376.991)*x);
plot(x,y,'r-*');
ax = gca;
ax.XAxis.Exponent = -3;
set(gca,'XTick',0:0.005:0.090);
set(gca,'YTick',-200:10:200);
xlabel('TIEMPO EN MILISEGUNDOS','Fontsize',20,'FontWeight','bold','Color','b')
ylabel('VOLTAJE','Fontsize',20,'FontWeight','bold','Color','b')
ax.YAxisLocation = 'origin';
ax.XAxisLocation = 'origin';
grid on;
grid minor;

Here's where I would like to position the Xlabel:

I would really appreciate your help!

Answer 1

[dpb]

You've got to override the default position data for the label when move the axis location to center--

Ylm=ylim;                          % get x, y axis limits 
Xlm=xlim;                          % so can position relative instead of absolute
Xlb=mean(Xlim);                    % set horizontally at midpoint
Ylb=0.99*Ylim(1);                  % and just 1% below minimum y value
hXLbl=xlabel('XLabel','Position',[Xlb Ylb],'VerticalAlignment','top','HorizontalAlignment','center'); 

"Salt to suit" positioning...having such in a callback function for axis resize/limits change would be needed to make it dynamically update.

[Przemyslaw Barnas]

Is it not easier to set pisition for xlabel than change default position data?

[dpb]

If you've not already drawn the plot, then sure...

[Nadav Arbel]

note that the line:

Ylb=0.99*Ylim(1); % and just 1% below minimum y value

will take the xlabel abouve the y minimum value if the axis has negative values.

It is best (IMHO) to calc 1% of the y axis min value:

OnePerc = 0.01*Ylim(1)

and subtract it from the min value:

Ylb=Ylim(1) - abs(OnePerc); % and just 1% below minimum y value

[Erfan Basiri]

I think in the third line, Xlim should be changed to Xlm, and Ylim to Ylm in the next line

Answer 2

[Przemyslaw Barnas]

Just add 'Position', [x y] in your xlabel

ex.

xlabel('TIEMPO EN MILISEGUNDOS','Position',[40 -205],'Fontsize',20,'FontWeight','bold','Color','b')

[dpb]

Yes, but the solution I gave is relative to the current y-axis lower ylim value and the middle of the xlim range so will be relative to the actual position. You've just hardcoded in a fixed number. That works for a specific case but only for the specific case/data values.

Answer 3

[Peter Seibold]

If you want a constant distance from the x axis, use this code:

% Move x label closer to x-axis, here 16 px
figure(1);
clf
plot(-5:10,-1:14)
ax=gca;
axOldUnits=ax.Units;% omit this line if ax units already in pixels
ax.Units='pixels';  % omit this line if ax units already in pixels
Ypx=ax.Position(4);                 % get axis height in px
Ylim=ylim;                          % get  y axis limits in data units
Xm=mean(xlim);                      % horizontal midpoint x axis
Data_px=(Ylim(2)-Ylim(1))/Ypx;      % Data units per pixel
DistXL = Ylim(1)-Data_px*16;        % Distance X-Label 16 px below x axis 
xlabel('My x-label','Position',[Xm DistXL],'VerticalAlignment','top','HorizontalAlignment','center'); 
ax.Units=axOldUnits;      % omit this line if ax units already in pixels