Changing order of legend entries when lslines are included

Hi, I am using MATLAB 2020a and have a graph that includes a legend with both data labels and lsline labels. I have tried suggestions to reorder the legend from

here: https://www.mathworks.com/matlabcentral/answers/654308-changing-order-of-legend-entries

here: https://matplotlib.org/1.3.1/users/legend_guide.html

and here: https://stackoverflow.com/questions/39103748/matlab-change-order-of-entries-in-figure-legend

However, they only seem to address situations where the labels are only coming from the data set(s) in the "plot" command. I have 4 data sets, plus 4 regression lines generated by lsline. The legend entries for lsline are in reverse order, but I can't figure out how to change them.

Here's some code:

figure;
p = plot([1 2;2 1;3 1;1 4]',[1 2;3 1; 4 5;2 4]');
p(1).LineStyle = 'none'; p(1).Marker = 'o'; p(1).MarkerSize = 5;
p(1).MarkerFaceColor = 'b'; p(1).MarkerEdgeColor = 'b'; p(1).DisplayName = '2016 CC';
p(2).LineStyle = 'none'; p(2).Marker = 's'; p(2).MarkerSize = 6;
p(2).MarkerFaceColor = 'b'; p(2).MarkerEdgeColor = 'b'; p(2).DisplayName = '2017 CC';
p(3).LineStyle = 'none'; p(3).Marker = 'o'; p(3).MarkerSize = 5;
p(3).MarkerFaceColor = 'r'; p(3).MarkerEdgeColor = 'r'; p(3).DisplayName = '2016 CS';
p(4).LineStyle = 'none'; p(4).Marker = 's'; p(4).MarkerSize = 6;
p(4).MarkerFaceColor = 'r'; p(4).MarkerEdgeColor = 'r'; p(4).DisplayName = '2017 CS';
h = lsline;
% colors and styles assigned in reverse order - not sure why
h(1,1).LineStyle = '-.'; h(1,1).Color = 'r';
h(1,2).LineStyle = '-'; h(1,2).Color = 'r';
h(1,3).LineStyle = '-.'; h(1,3).Color = 'b';
h(1,4).LineStyle = '-'; h(1,4).Color = 'b';

legend('2016 CC','2017 CC','2016 CS','2017 CS',...
'2017 CS','2016 CS','2017 CC','2016 CC');

Which results in this graph:

The lsline entries are in reverse order, which is reflected in the legend. Rearranging the lsline line assignments would be one fix to my specific issue. But specifically I'm asking how to fix it in the legend.

Thanks in advance.

Answer 1

[Kelly Kearney]

The easiest way to be certain your legend labels match up is to pass handles specifically:

figure;
p = plot([1 2;2 1;3 1;1 4]',[1 2;3 1; 4 5;2 4]', 'o');
h = lsline;
legend([p' h], '1p','2p','3p','4p','4ls','3ls','2ls','1ls');

The ordering is due to how lsline looks for plotted datasets to regress... it uses get(gca, 'Children'), which always returns plotted objects in reverse stacking order (i.e. top to bottom); in most cases this will mean moving from the most-recently plotted object backwards.

[Ellen Maas]

Thank you for the explanation, Kelly. Although it didn't answer my question per se (how to reorder the lsline legend entries), it provided the missing piece. So with your code that shows how to use both of the handles in the "legend" command, I was able to reorder the lsline entries using Suever's suggestion at https://stackoverflow.com/questions/39103748/matlab-change-order-of-entries-in-figure-legend

This is what I have now:

figure;
p = plot([1 2;2 1;3 1;1 4]',[1 2;3 1; 4 5;2 4]');
p(1).LineStyle = 'none'; p(1).Marker = 'o'; p(1).MarkerSize = 5;
p(1).MarkerFaceColor = 'b'; p(1).MarkerEdgeColor = 'b'; p(1).DisplayName = '2016 CC';
p(2).LineStyle = 'none'; p(2).Marker = 's'; p(2).MarkerSize = 6;
p(2).MarkerFaceColor = 'b'; p(2).MarkerEdgeColor = 'b'; p(2).DisplayName = '2017 CC';
p(3).LineStyle = 'none'; p(3).Marker = 'o'; p(3).MarkerSize = 5;
p(3).MarkerFaceColor = 'r'; p(3).MarkerEdgeColor = 'r'; p(3).DisplayName = '2016 CS';
p(4).LineStyle = 'none'; p(4).Marker = 's'; p(4).MarkerSize = 6;
p(4).MarkerFaceColor = 'r'; p(4).MarkerEdgeColor = 'r'; p(4).DisplayName = '2017 CS';
h = lsline;
% colors and styles assigned in reverse order - not sure why
h(1,1).LineStyle = '-.'; h(1,1).Color = 'r';
h(1,2).LineStyle = '-'; h(1,2).Color = 'r';
h(1,3).LineStyle = '-.'; h(1,3).Color = 'b';
h(1,4).LineStyle = '-'; h(1,4).Color = 'b';
neworder = [4,3,2,1];
legend([p' h(neworder)], '2016 CC','2017 CC','2016 CS','2017 CS',...
'2016 CC','2017 CC','2016 CS','2017 CS');

Which results in this:

Thanks for your help!