Add xline equivalent to stackedplot?

Hi there,

I recently started using stackedplot instead of subplot, but I'm not sure how to add a line from 0 to my Y-axis-limit while using the stackedplot funciton.

While using subplot in the past, I have been able to use xline(0) or vline(0) to represent a stimulus onset time when comparing evoked responses across a certain timecourse. I.e.

%%%%% Using xline in subplots
close all
time = -150:1:349; %This is time in ms relative to stimulus onset at time 0
maxYval = max(max(PlotThis));
figure
for i = 1:3
    subplot(3,1,i)
    plot(time,PlotThis(:,i));
    hold on
    xline(0)
    ylim([0 maxYval])
end

I would like to use stackedplots instead of subplot because it is much easier to edit and manage when I have several plots with the same x-axis. The one drawback is that stackedplots does not allow the "hold on" feature so xline(0) or vline(0) does not work. I can insert a line in-post on the matlab figure editor, but is there a way to do this programitically?

i.e.

%%% using stackedplot
figure
s = stackedplot(time,PlotThis);
s.AxesProperties(1).YLimits = [0 maxYVal];
s.AxesProperties(2).YLimits = [0 maxYVal];
s.AxesProperties(3).YLimits = [0 maxYVal];

and inserting a line on the matlab figure editor yields:

Thank you!

Answer 1

[Adam Danz]

You can get the axis handles in stackedplot using the undocumented NodeChildren property. Then use xline to add vertical reference lines.

rng('default')
h = stackedplot(-10:10,rand(21,4)); 
ax = findobj(h.NodeChildren, 'Type','Axes');
arrayfun(@(h)xline(h,0,'LineWidth',1.5),ax)

% Starting R2021a, xline and yline can accept an array of handles
% xline(ax,0,'LineWidth',1.5)

Also see Ameer Hamza's approach using an annotation line.

[Brock Carlson]

Adam,

Thank you so much! This is a fascinating work-around. I was able to get this to work with my code.

As a result, I have unaccepted Payas' answer and accepted yours. Should MathWorks create a formal solution in the future I will try to update that here.

[Adam Danz]

Glad I could help.

I just updated the answer with a better way to get axis handles.

[Christina Diersing]

Is there a way to add labels to these lines? I want to add a label, such as Ns, Ea, Md, etc. to the lines (I have the array of labels below and I attached the snap of the figure - the figure itself was too large to attach, even in a zip file).

['Ns','08','15','22','Ns','Ec','Mo','Ns','08','15','22','Ns','Mo','Mt','Ea','Md','Hr','Mt','Mt','Ea','Md','Hr']

[Adam Danz]

Yes, the 3rd input to xline is the label in the form of a string or character array.

help xline

[Christina Diersing]

Thank you!

This is a similar bit of code I used for the same purpose:

    sp=stackedplot(T,T.Properties.VariableNames(2:end),'XVariable','Timestamp')
    ax = findobj(sp.NodeChildren, 'Type','Axes');
    arrayfun(@(sp)xline(sp,EvtMar,'--',{'EO','BE','BE','BE','EC','BE','CE','CE','BE','OM','OM'}),ax);
    grid on; xlabel('Timestamp (s)'); %turns on grid and labels the x-axis
    title('EEG Signals - Stacked Plot');
    fig0.WindowState = 'maximize'; %maximizes the figure window -> easier to see

[Adam Danz]

I don't know when this option became available but in Matlab R2021b you can enter mutliple values for xline and yline.

xline(1:5,'k-', {'a' 'b' 'c' 'd' 'e'})

xlim([1,5.5])

[Oscar]

Great answer. Unfortunately, this method doesn't seem to work when the figure is embedded in a Live Script.

Answer 2

[Payas Bahade]

Hi Brock,

Currently there is no xline equivalent in stacked plots. I have informed the concerned teams and they would be looking into this issue.

[Brock Carlson]

Thank you very much! I'll be excited to see updates if they become available.

[Nicolas]

Hello Payas,

Any update on this? Stacked plots are really neat to quickly draw stuff, adding the ability to add annotations such as vline would be a real plus!