Take a look at this function, it fades a plot and add new data on it.
https://www.mathworks.com/matlabcentral/fileexchange/69816-fadeit

There is an issue when there are too many points in the plot as Sebastian pointed out above. Below 25000 points, everything works as expected:

% define
N   = 25000;
t   = linspace(0,4*pi,N);
x   = 27*cos(t) + 29*cos(27/2*t);
y   = 27*sin(t) - 29*sin(27/2*t);
 
% plot
hFig  = figure('Units','normalized','Position',[0.2 0.2 0.4 0.5]);
hAxes = axes('XTick',{},'YTick',{},'NextPlot','replacechildren','Box','on');
hPlot = plot(x,y);
axis equal tight;
drawnow(); % as required
%
hPlot.Edge.ColorBinding = 'interpolated';
hPlot.Edge.ColorData    = [uint8(parula(N)*255) 255*ones(N,1,'uint8')]';

Above this magic number, Matlab tries to optimize the figure by plotting only a subset of the vertices. Repeating the procedure with more points than that results in a warning and no color gradient:

N   = 25001;
...
hPlot.Edge.ColorData    = [uint8(parula(N)*255) 255*ones(N,1,'uint8')]';

Warning: Error creating or updating LineStrip
 Error in value of property  ColorData
 Array is wrong shape or size

To fix the issue, we need to probe the number of vertices in hPlot.Edge:

N   = 25001;
...
N2  = size(hPlot.Edge.VertexData,2);
hPlot.Edge.ColorData = [uint8(parula(N2)*255) 255*ones(N2,1,'uint8')]';

But, if we try, say, to resize the figure, the warning reappears (though the gradient stays):

drawnow(); % just in case...
hFig.Position = [0.2 0.2 0.5 0.6];

Warning: Error creating or updating LineStrip
 Error in value of property  ColorData
 Array is wrong shape or size

Similar unexpected behavior occurs in zoom, copyobj etc.

P.S, my Matlab version is R2018a, so it looks like a rather persistent problem.

I am trying to plot a line with a gradient which would be “perpendicular” to the line. For example:

N = 10;
p = plot(1:N, ones(1, N), ‘Linewidth’, 20);
cd = [uint8(jet(N)*255) uint8(ones(N, 1))].’;
drawnow
set(p.Edge, ‘ColorBinding’,’interpolated’, ‘ColorData’,cd)

This is a horizontal line with color gradient going from left to right (in the direction of the sample points). Is there a way to have a gradient going from top to bottom? (if the line is tilted, then the gradient would be still perpendicular to that line). The effect should look like the line is fading out in the perpendicular direction.

Thanks for any hints and ideas.

[p1, p2] = m_contour(x, y, z, 'color',[0.0 0.5 1.0], 'linewidth',1.5)
hold on
p2.Color(4) = 0.3

This doesn’t work. Is there a possibility to solve that problem?
Thanks!

Is it possible to load the value of transparency and store it in some variable? e.g. x = h2b.Color(4).
I get the error ‘Index exceeds matrix dimensions.’ when I try this. Is there anyway to load this value?

Thanks!

Do you known if there is an “outline.Color” property for the “line” object? It would make 3D objects much more readable in terms of what is front and what is back (get rid of the Necker illusion). See, e.g., https://en.wikipedia.org/wiki/File:4Asterane.png

Thanks!

xlim([1,5]);
hold('on');
cd = uint8([255,200,250,50,0; 0,50,250,150,200; 0,0,0,100,150; 179,150,200,70,50]);
h2b = plot(2:6,  15:-1:11, '.-r', 'LineWidth',8, 'DisplayName',' 0.7'); 
set(h2b.Edge, 'ColorBinding','interpolated', 'ColorData',cd , 'ColorType','truecoloralpha');

The codes are almost exactly as yours, except that I set the ‘ColorType’ since it is ‘truecolor’ in default.
However, the line is not a transparent one. I checked the h2b.Edge and found that the ColorBinding is still ‘object’. Then I run the last sentence of the above codes in Command Window again. This time it works and the line is transparent as your results.
Could you please tell me why would this happen and how to fix it? Because I would like to use it to generate some pictures and it’s a disaster if I have to run the last sentence in Command Window each time.
Thanks!
PS, the version of my MATLAB is R2015a.