This may get you started:
function vertical_cursors
set(gcf, ...
'WindowButtonDownFcn', @clickFcn, ...
'WindowButtonUpFcn', @unclickFcn);
% Set up cursor text
allLines = findobj(gcf, 'type', 'line');
hText = nan(1, length(allLines));
for id = 1:length(allLines)
hText(id) = text(NaN, NaN, '', ...
'Parent', get(allLines(id), 'Parent'), ...
'BackgroundColor', 'yellow', ...
'Color', get(allLines(id), 'Color'));
end
% Set up cursor lines
allAxes = findobj(gcf, 'Type', 'axes');
hCur = nan(1, length(allAxes));
for id = 1:length(allAxes)
hCur(id) = line([NaN NaN], ylim(allAxes(id)), ...
'Color', 'black', 'Parent', allAxes(id));
end
function clickFcn(varargin)
% Initiate cursor if clicked anywhere but the figure
if strcmpi(get(gco, 'type'), 'figure')
set(hCur, 'XData', [NaN NaN]); % <-- EDIT
set(hText, 'Position', [NaN NaN]); % <-- EDIT
else
set(gcf, 'WindowButtonMotionFcn', @dragFcn)
dragFcn()
end
end
function dragFcn(varargin)
% Get mouse location
pt = get(gca, 'CurrentPoint');
% Update cursor line position
set(hCur, 'XData', [pt(1), pt(1)]);
% Update cursor text
for idx = 1:length(allLines)
xdata = get(allLines(idx), 'XData');
ydata = get(allLines(idx), 'YData');
if pt(1) >= xdata(1) && pt(1) <= xdata(end)
y = interp1(xdata, ydata, pt(1));
set(hText(idx), 'Position', [pt(1), y], ...
'String', sprintf('(%0.2f, %0.2f)', pt(1), y));
else
set(hText(idx), 'Position', [NaN NaN]);
end
end
end
function unclickFcn(varargin)
set(gcf, 'WindowButtonMotionFcn', '');
end
end
Save the above function. Here's an example of how to use it:
subplot(221);
plot(rand(10,1));
subplot(222);
plot(rand(10,2));
subplot(223);
plot([rand(10,1), rand(10,1)+1]);
subplot(224);
plot(rand(10,1));
vertical_cursors;
EDIT: As a response to a request, I added the ability to make the cursor disappear when clicking outside the axes. See the two lines of code with the comment "<-- EDIT".
