Legend is not displayed in my plot

I tried to plot a data where there are two x-axis. Therefore I created plot, and two x-axis and then when I try to display the legend, it is not shown.

Problem I found

• Legend is stacked behind the axes and therefore not visible

Things I tried

• Getting legend to the top using Uistack command
• Bringing the axes layers to the bottom using the following command

set(ax1, 'Layer', 'bottom'); % set axes to be behind the legend
set(ax2, 'Layer', 'bottom'); % set axes to be behind the legend

This also didn't work.

Below is my following code. I will attach the input data along with this file.

If my understanding is correct, the legend is stacked on the back and we need to bring them forward. I need help with this.

%% Plot Raw data with two x-axis
load("matlab.mat")

lim_1 = 600;                               % Enter the limits here for the plot
lim_2 = 900;                               % Enter the limits here for the plot

wv_tik  = lim_1:50:lim_2;                  % Modify this if needed
E_tik   = round(1240./wv_tik,2);

figure;
for i = 1:length(Data)
    
    plot(Data(i).data(:,1), Data(i).data(:,2), LineWidth=1.5);
    ax1 = gca;        % get current axis
    ax1.XColor = 'k'; % set bottom x-axis color to black
    ax1.YColor = 'k'; % set left y-axis color to blue
    ax1.XLim   = [lim_1 lim_2];
    ax1.XMinorTick = 'on'; 
    hold on
    % Add a second x-axis on top
    ax2 = copyobj(ax1,gcf);
    ax2.XColor = 'k'; % set top x-axis color to red
    ax2.XTick  = wv_tik;
    ax2.XLim   = [lim_1 lim_2];
    ax2.XTickLabel = E_tik; % remove tick labels for top x-axis
    ax2.XAxisLocation = 'top'; % set location of top x-axis
    ax2.YTick = []; % remove tick marks for top x-axis
    ax2.XMinorTick = 'on';

    % Set the Visible property of the axes object to 'on'
%     set(ax1, 'Visible', 'on');
%     set(ax2, 'Visible', 'on');
end
hold off

xlabel('Wavelength ($\mu$m)', 'Interpreter', 'latex', 'FontSize', 14);
ylabel('PL ', 'Interpreter', 'latex', 'FontSize', 14);
set(gca,'FontSize',14); % set font size for the axis labels and tick marks
legend('Juni','Interpreter', 'latex', 'FontSize', 14, 'Location', 'eastoutside');
set(ax1, 'Layer', 'bottom'); % set axes to be behind the legend
set(ax2, 'Layer', 'bottom'); % set axes to be behind the legend

Answer 1

[Raghunathraju]

Hi

As per my understanding you want to display legend in your plot, but you are unable to see it as it is behind the axes ax2.It is because of the differences in dimensions of ax1 and ax2 .

You can simply do the following change in the code

ax2.Position=ax1.Position;

I can demonstrate the same with some changes in your code.

%% Plot Raw data with two x-axis
load("matlab.mat")
lim_1 = 600;                               % Enter the limits here for the plot
lim_2 = 900;                               % Enter the limits here for the plot
wv_tik  = lim_1:50:lim_2;                  % Modify this if needed
E_tik   = round(1240./wv_tik,2);
figure;
for i = 1:length(Data)
    plot(Data(i).data(:,1), Data(i).data(:,2), LineWidth=1.5);
end
ax1 = gca;        % get current axis
ax1.XColor = 'k'; % set bottom x-axis color to black
ax1.YColor = 'k'; % set left y-axis color to blue
ax1.XLim   = [lim_1 lim_2];
ax1.XMinorTick = 'on'; 
hold on
% Add a second x-axis on top
ax2 = copyobj(ax1,gcf);
ax2.XColor = 'k'; % set top x-axis color to red
ax2.XTick  = wv_tik;
ax2.XLim   = [lim_1 lim_2];
ax2.XTickLabel = E_tik; % remove tick labels for top x-axis
ax2.XAxisLocation = 'top'; % set location of top x-axis
ax2.YTick = []; % remove tick marks for top x-axis
ax2.XMinorTick = 'on';
xlabel('Wavelength ($\mu$m)', 'Interpreter', 'latex', 'FontSize', 14);
ylabel('PL ', 'Interpreter', 'latex', 'FontSize', 14);
set(gca,'FontSize',14); % set font size for the axis labels and tick marks
legend('Juni','Interpreter', 'latex', 'FontSize', 14, 'Location', 'eastoutside');
ax2.Position=ax1.Position;

Now you can see your expected result. I hope this resolves the issue.

[Master]

Yes but it does not come on top the axis where the plot is there. For instance, if I remove the location of legend, it is not visible. I think there is a problem in the way I coded to get to 2 X-axis and 1 yaxis.

[Image Analyst]

Try

title('Juni','Interpreter', 'latex', 'FontSize', 14);

or else use

text(x, y, 'Juni');

to place it wherever you want.

[Raghunathraju]

You can make ax2 as the parent of legend to get the legend on top of the axis ax2.

Try something like this

legend(ax2,'Juni','Interpreter', 'latex', 'FontSize', 14);

Fore more information refer to axes and legend

Answer 2

[Dyuman Joshi]

%% Plot Raw data with two x-axis
load("matlab.mat")

lim_1 = 600;                               % Enter the limits here for the plot
lim_2 = 900;                               % Enter the limits here for the plot

wv_tik  = lim_1:50:lim_2;                  % Modify this if needed
E_tik   = round(1240./wv_tik,2);

    figure
    plot(Data.data(:,1), Data.data(:,2), 'LineWidth',1.5)
    ax1 = gca;
    ax1.XColor = 'k'; % set bottom x-axis color to black
    ax1.YColor = 'b'; % set left y-axis color to blue
    ax1.XLim   = [lim_1 lim_2];
    ax1.XMinorTick = 'on';      
    xlabel(ax1,'Wavelength ($\mu$m)', 'Interpreter', 'latex', 'FontSize', 14);
    ylabel(ax1,'PL', 'Interpreter', 'latex', 'FontSize', 14);
    legend(ax1,'Juni','Interpreter', 'latex', 'FontSize', 14)%, 'Location', 'eastoutside') 

    %Create a new axes at same position rather than copying
    %and modify it accordingly
    ax2=axes('Position',ax1.Position);
    ax2.XAxisLocation = 'top'; % set location of top x-axis
    ax2.XColor = 'r'; % set top x-axis color to red
    ax2.XLim   = [lim_1 lim_2];
    ax2.XTick  = wv_tik;
    ax2.XTickLabel = E_tik;
    ax2.XMinorTick='on';
    ax2.YAxisLocation = 'right'; % set location of top y-axis
    ax2.YColor = 'y';    
    ax2.YTick = [];
    ax2.Color = 'none';