What is wrong with my legend?

Hey people,

So I have this Code

% linestyle       = {'-' '--' ':'};
color           = {'b' 'k' 'y'};
force_index     = {'X' 'Y' 'Z'};
TITLE           = {'Test 008-2 - floating buoy';'Test 033-1 - submerged buoy'};
test_no         = {'Test_008_2';'Test_033_1'};
perc_Matrix     = ones(3,2);

% Plot Ratios
for t=1:2

      figure
      set(gcf, 'Visible', 'off')
      box on
      hold on

      for d=1:3

          F_XX            = Force(t).Tests(d).Data;
          time_XX         = Force(t).Tests(5).Data;
          Resultant_XX    = Force(t).Tests(4).Data;

          time_N = normalize(time_XX,'range');

          yaxis = abs(F_XX)./Resultant_XX;
          yaxis = sortrows(yaxis);

          plot(time_N,yaxis,color{d},'LineWidth',2)

          ylabel('F/F_R [-]')
          xlabel('Normalized sample range [-]')
          xmin = 0;
          xmax = 1;
          xlim([xmin xmax])

          % Calculate percentiles
          semilogy(time_N,yaxis);
          if t==1
              y = 0.9;
          elseif t==2
              y = 0.5;
          end
          percentile = interp1(yaxis,time_N,y);
          perc_Matrix(d,t) = 100-ceil(100*percentile);

          line([0 percentile],[y y],'Color','black','Linewidth',0.01,'LineStyle',...
              ':','HandleVisibility','off');
          line([percentile percentile],[0 y],'Color','black','Linewidth',0.1,'LineStyle',...
              ':','HandleVisibility','off');

          lgd             = ['F_' force_index{d} '/F_R'];
          legendInfo{d}   = (lgd);

      end

      legend(legendInfo,'Location','northwest')

      orient(gcf,'portrait')
      set(gcf,'PaperPosition',[0 0 47 24])
      set(findall(gcf,'-property','FontSize'),'FontSize',16)

      tit = [char(TITLE(t)) ' - Ratios of Forces X,Y,Z to Resultant'];
      title(tit,'FontSize',18)

      set(findall(gcf,'-property','FontName'),'FontName','SansSerif')
      saveas(gcf,[char(test_no(t)) '.tif']);

      close

end

When I run it everything is fine except the legend in my tif-file (also in mat figure). The colors in the legend are just not right and I have no idea why. It looks like this:

Fz/Fr should be yellow and Fy/Fr should be black. Only Fx/Fr is right. I attached the used Force structure.

Maybe anybody can help me?:)

Thank you

Answer 1

[Prateekshya]

Hello @Stwiwi,

The issue with the legend colors not matching the plotted lines in your MATLAB code could be due to the legend not associating each entry with the corresponding plot. Here is a sample code which you can utilize to modify your code:

% Sample data
time = linspace(0, 1, 100); % Normalized time from 0 to 1
data1 = sin(2 * pi * time); % Sample data for X
data2 = cos(2 * pi * time); % Sample data for Y
data3 = sin(2 * pi * time + pi/4); % Sample data for Z

% Colors for each plot
colors = {'b', 'k', 'y'};
labels = {'Data X', 'Data Y', 'Data Z'};

% Create figure
figure;
hold on;

% Plot each dataset and store plot handles
plotHandles = gobjects(1, 3); % Preallocate plot handles
plotHandles(1) = plot(time, data1, 'Color', colors{1}, 'LineWidth', 2);
plotHandles(2) = plot(time, data2, 'Color', colors{2}, 'LineWidth', 2);
plotHandles(3) = plot(time, data3, 'Color', colors{3}, 'LineWidth', 2);

% Add labels
xlabel('Normalized Time');
ylabel('Amplitude');
title('Sample Data Plot');

% Create legend using plot handles
legend(plotHandles, labels, 'Location', 'northwest');

% Display the plot
hold off;

After running this code, the below figure is obtained as the output. In this figure, the legends are matched with the respective plots correctly.

For more information on legends, please follow the below link:

https://www.mathworks.com/help/matlab/creating_plots/add-legend-to-graph.html

I hope this helps!