Get next plot color

When using the function plot with hold set to 'all', each call to plot uses the successive entry in the ColorOrder property of the current axes. Is there a way to find out what is the color the next call to plot will use, if it is not known how many calls to plot have already been executed?

In other words, here is an example to clarify my question: plot(x,bob) hold all plot(x,garry) ... (unknown number of calls to plot)

What will be the color of the next plot?

Thanks, David

[Walter Roberson]

Good question. I think I came across the answer once before, but in poking around now, I see that the operations are ugly. For example, plotyy() plots the first plot, counts the number of lines in it, and sets a new defaultaxescolororder by shifting the existing order by the number of lines already plotted.

[Daniel Shub]

plotyy is interesting since it actually makes an extra axis. I think most plotting functions now only add a single child to the axis. For example, I believe errorbar used to add multiple children.

[Walter Roberson]

There are many plotting functions that add multiple children -- though the top level child might be an hggroup .

plot() adds multiple line() objects; bar() adds multiple patch() objects; boxplot() adds a combination of objects; polar() adds a combination of objects; contour() adds an hggroup that has patch() objects and text() objects as its children...

[David C]

Thank you for the input everyone.

Answer 1

[Daniel Shub]

I think the number of children should equal the number of calls to plot. You need to use mod to loop through the colors (i.e if the number of plots is greater than the number of colors).

colorOrder = get(gca, 'ColorOrder');
plot(1:10, 'Color', colorOrder(mod(length(get(gca, 'Children')), size(colorOrder, 1))+1, :))

[Daniel Shub]

To deal with Walter's observation about plotyy, I guess you would need to check the figure for all children which are axes. You then might want to count the children of any axes which have identical positions to the axis you are interested in.

[David C]

Your code works well with plot(), which is what I'm using. I like how your code handles the corner cases with mod perfectly.

Answer 2

[Jan]

What about trying it:

lineH = plot(1,1);
color = get(lineH, 'Color');
delete(lineH);

[EDITED]: Walter's comment pointed me to the fact, that the intermediate creation of a PLOT line changes the next color. This is not working

[Walter Roberson]

Hmmm -- would the next plot() after that re-use the now-available color, or would it consider it to have been "already used" and move on to the color after that?

[David C]

Although not ideal for the purpose I had in mind, it is a good idea.

[Alexandra Gallyas Sanhueza]

I was actually searching how to advance to the next color and this works :)

Answer 3

[Teja Muppirala]

This seems to work ok:

figure
hold all;
plot(rand(5,3));

h = plot(nan,nan);
nextcolor = get(h,'color')
h = plot(nan(2,size(get(gca,'colororder'),1)-1)); %Loop back
delete(h)

plot(rand(1,10)) %<-- This line's color is "nextcolor"

[Walter Roberson]

Heh. ;-)

[David C]

This is very clever; thank you. As Daniel's answer was the first that worked for me, I have accepted his answer.

[Jan]

If the LineStyleOrder is not scalar, it should be considered also.

Answer 4

[John Barber]

The next color to be used by a call to plot is stored as an index into the list of colors in the axes' ColorOrder property. You can access this index using:

NextColor = getappdata(hAx,'PlotColorIndex')

where hAx is the handle of the axes of interest. This is an undocumented feature, so it may not work in all MATLAB versions (I'm using R2010a / 7.10)

Answer 5

[Jim Hokanson]

In newer versions of Matlab the state is stored in the axes as 'ColorOrderIndex'. In 2016b, this wraps, and you can get values from 1 to (n_colors+1) which after (n_colors+1) goes back to 2 (you only see 1 at the start of a plot, at least in this version).

So the next color is:

colors = get(gca,'ColorOrder');
index  = get(gca,'ColorOrderIndex');
n_colors = size(colors,1);
if index > n_colors
  index = 1;
end
next_color = colors(index,:);

[J. Alex Lee]

Update in 2020 (not sure about previous versions), but it is now an exposed property in the axes:

ax = gca;
ax.ColorOrder
ax.ColorOrderIndex

Works for uiaxes() as well

Answer 6

[Mauro]

to get the colour from the 1th to the 20th lineplot, type

cm = lines(20);

after the 7th line it starts again with blue [0 0 1]

so

figure(1)
clf
plot(randn(50,10)*0.1+repmat((1:10),50,1))

ist the same as

figure(1)
clf
cm = lines(10)
hold on
for k = 1:10
    plot(randn(50,1)*0.1+k,'color',cm(k,:))
end