How to slide a plotted line in matlab figure - matlab

Question

I am plotting a sin and cosine using below code:
x = 0 : 0.1 : 2*pi ;
y1 = sin (x) ;
y2 = cos (x) ;
figure ;
plot(x,y1) ;
hold ;
plot(x,y2,'r')
I want to move/slide the line corresponding to sin in order to overlay on top of line corresponding to cos and want to achieve it without moving pan. I searched ob web but unable to find a simple solution.

Answer 1

You can plot your 2 sinus/cosinus within a function, then use a callback to update your plot, here I update the phase of the sinus plot in the callback function call_S:
function [] = slider_plot()
% Plot different plots according to slider location.
S.fh = figure('position',[300 300 300 300],....
'resize','off');
S.x = 0:.01:4*pi; %range.
S.ax = axes('unit','pix',...
'position',[20 80 260 210]);
S.sin = plot(S.x,sin(S.x),'r'); %sinus phase will move
hold on
S.cos = plot(S.x,cos(S.x),'b');
S.sl = uicontrol('style','slide',...
'position',[20 10 260 30],...
'min',0,'max',3*pi/2,'val',0,... %default phase = 0
'sliderstep',[0.1 0.1],...
'callback',{#call_S,S});
function [] = call_S(varargin)
% Callback for the phase slider.
[h,S] = varargin{[1,3]}; % calling handle and data structure.
set(S.sin,'ydata',sin(S.x + get(h,'value'))) %set the new phase
I use a slider in this case, but you could also use the position of your mouse to determine the new phase.
Result:
And you can move the slider to shift the phase:

Answer 2

Many thanks to #obchardon:
Below is updated version of his code which meet my requirements:
function [] = slider_plot2()
x = 0 : 0.1 : 4*pi ;
y1 = sin (x) ;
y2 = cos (x) ;
% Plot different plots according to slider location.
S.fh = figure('position',[300 300 500 500],....
'resize','off');
S.x = x; %range.
S.y2 = y2 ;
S.ax = axes('unit','pix',...
'position',[30 80 460 410]);
S.line2 = plot(S.x,y2,'r'); %sinus phase will move
hold on
S.line1 = plot(S.x,y1,'b');
S.sl = uicontrol('style','slide',...
'position',[20 10 260 30],...
'min',1,'max',length(x),'val',1,... %default phase = 0
'sliderstep',[1 1],...
'callback',{#call_S,S});
function [] = call_S(varargin)
% Callback for the phase slider.
[h,S] = varargin{[1,3]}; % calling handle and data structure.
currentPosition = floor(get(h,'value')) ;
ydata = S.y2(currentPosition:end) ;
xdata = S.x(1:end-currentPosition+1) ;
set(S.line2,'xdata',xdata,'ydata',ydata) %set the new phase
%set( S.line2,'ydata',ydata) %set the new phase