How to align both vertically and horizontally annotation box with legend box in plots?

I want to get the horizontal and vertical alignment of annotation box with the legend box to give simmetry to my plots.

Here is a reproducible example of my typical code I use to get these kind of plots:

clc;clear all; close all;

x= linspace(0,2*pi,1000);
y= sin(x-2);
plot(x,y)
legend('y=sin(x-2)');
grid on;

% Extra info box
dim = [.168 .80 .20 .06];
str = 'info box';
annotation('textbox',dim,'String',str,'Interpreter',"latex",'FitBoxToText','on',...
           'BackgroundColor',[1 1 1],'FontSize',9);

Look at the following figure to better consider my problem: I want that the distances represented by the red segment are equal, and the same for the distances represented by the blue segments.

Can you help me to get these alignements?

Is there a way to give to "annotation" the same properties of legend command as "north, east, northwest, etc."?

[Star Strider]

@Giuseppe — With respect to exporting the figures, there are other options, specifically saveas that can save to a number of formats including .pdf. Experimenting with it could be an option.

[Giuseppe]

@Star Strider thanks very much for the suggestion. I use "exportgraphics" to minimize the white space around the content.

Can you take a look at my code in the last comment of the accepted answer below?

I have an unexpected issue whith horizontal alignment of legend and annotation boxes.

[Star Strider]

My pleasure.

That is the reason I suggested an alternative.

First, be sure that you have all the latest MATLAB updates, since an update could have solved that problem already.

If it persists after all the updates, I recommend that you Contact Support with respect to the exportgraphics problem. MathWorks may have a work-around for it, or may not know that you are experiencing is a problem with it. They need to know that if there is going to be a fix for it.

[Giuseppe]

Thank you again. So, I think it's time to update to R2022b. I did not yet update because I'm very busy with my thesis.

Because of bad experience with a Microsoft Visual studio update, I'm a little bit afraid when there is a new update to do.

[Star Strider]

My pleasure!

I was referring to R2022a updates (top toolstrip: RESOURCES —> Help —> Check for Updates), however I definitely recommend R2022b.

I have rarely had problems with MATLAB interim updates, and upgrades to new releases. A few years ago, one new release failed to import my preferences and that required about an extra half hour of work to get those imported, however the others have gone seamlessly.

Answer 1

[Simon Chan]

"annotation" dose not have properties of legend command as north, east,...

I think you may need to calculate the margin separately as follows:

x= linspace(0,2*pi,1000);
y= sin(x-2);
plot(x,y)
ax=gca;
lgd=legend('y=sin(x-2)');
grid on;
% Extra info box
dim = [.168 .80 .20 .06];
str = 'info box';
an=annotation('textbox',dim,'String',str,'Interpreter',"latex",'FitBoxToText','on',...
           'BackgroundColor',[1 1 1],'FontSize',9);
%% Calculate the required margins
newx = ax.InnerPosition(1)+ax.InnerPosition(3)-(lgd.Position(1)+lgd.Position(3))+ax.InnerPosition(1);
newy = lgd.Position(2)+lgd.Position(4)-an.Position(4);
set(an,'Position',[newx newy an.Position(3) an.Position(4)]);

[Giuseppe]

Thank you @Simon Chan, your solution is a little bit laborious for me but it solves my problem. Do you know an alternative to annotation that is easier to manage?

[Simon Chan]

I don't think of any idea for an alternative.

On the other hand, you many manually assign the inner position of the axis, legend position and the annotation position separately which is relatively easier.

[Giuseppe]

Hi @Simon Chan I tried this method with a figure with "axis equal" property and it does not work. Any ideas to fix it?

Can you modify your solution to get in account of customized aspect ratio of the figure?

I usually use:

axis equal

or one of thwo following ones:

set(gcf,'position',[400, 200, 560, 315]);  %Aspect ratio: 16/9
set(gcf,'position',[278.6, 0.2, 600, 400]);  %aspect ratio 3/2

[Simon Chan]

I try to add "axis equal" and the result looks aceptable (Visually check).

I suggest to use "normalized" instead of "pixels" as the Units for all objects incuding the axis itself.

x= linspace(0,2*pi,1000);
y= sin(x-2);
plot(x,y)
ax=gca;
axis(ax,'equal');                   % <--Axis equal added here
lgd=legend('y=sin(x-2)');
grid on;
% Extra info box
dim = [.168 .80 .20 .06];
str = 'info box';
an=annotation('textbox',dim,'String',str,'Interpreter',"latex",'FitBoxToText','on',...
           'BackgroundColor',[1 1 1],'FontSize',9);
%% Calculate the required margins
newx = ax.InnerPosition(1)+ax.InnerPosition(3)-(lgd.Position(1)+lgd.Position(3))+ax.InnerPosition(1);
newy = lgd.Position(2)+lgd.Position(4)-an.Position(4);
set(an,'Position',[newx newy an.Position(3) an.Position(4)]);

[Giuseppe]

Hi @Simon Chan I did several attempts but with no succes!

Can you take a look at my code:

load UHIM_DB_light.mat
load Customized_colors

num_orbits       = 2;  % Number of orbits for each value of JC
num_orbit_points = 200;  % Number of points for each orbit 
array_manif_idx  = 1:1:numel(UHIM_DB(1).data(1).PLO_to_CI);
idx_manif_traj = 1;
% Matrix containing 200 HIM trajectories (200 points for each trajectory)
matrix_traj_idx = reshape(array_manif_idx,[num_orbit_points,num_orbits]) ;
indices_Manif_traj = matrix_traj_idx(:,idx_manif_traj); 
mu = 3.040423426440150e-06;
idx_JC    = 3;   
factor_k  = 2;
au2km     = 1.495978707e+08;
r_Laplace_SOI=9.29e+05;
rCI_EM_km = factor_k .* r_Laplace_SOI;

fig = figure;
hold on; axis equal; grid on; box on;

traj_colors =  [1 0.3 0.3;0.3 0.8 0.9];
txt_pts_offset =[+0.1e+6,+0.9e+5;+0.1e+6,-0.3e+6];
text_pos =[-0.0012,-0.0025;-0.00075,-0.0025];
r_CI_lgd = ['$r_{CI} =\ $',num2str(rCI_EM_km,'%3.2e'),'$\ km$'];
% Plot CI
CI_plot=plotCircle((mu-1)*au2km,0*au2km,rCI_EM_km,[0 1 0],0.7,r_CI_lgd);
num_L_points = 2;
colors_PLO = [my_red;my_blue];
traj_plot = zeros(1,numel(num_L_points)); % preallocation
% Plot trajectories of unstable manifold
for idx_L=1:num_L_points
    lgd_label         = ['$JC =\ $',num2str(UHIM_DB(idx_L).data(idx_JC).JC,'%9.6f')];
   
    % Plot PLOs
    plot([UHIM_DB(idx_L).data(idx_JC).PLO.x]*au2km,[UHIM_DB(idx_L).data(idx_JC).PLO.y]*au2km,...
         '--','Color',colors_PLO(idx_L,:),'LineWidth',1.0);

    % Plot trajectories
    manif_traj = UHIM_DB(idx_L).data(idx_JC).PLO_to_CI(indices_Manif_traj);
                 traj_plot(idx_L)=plot([manif_traj.x]*au2km,[manif_traj.y]*au2km,...
                 'Color',traj_colors(idx_L,:),'LineWidth',0.5,'DisplayName',lgd_label); 

    % Plot initial point
    pt_I = [[manif_traj(1).x]*au2km,[manif_traj(1).y]*au2km];
           plot(pt_I(1),pt_I(2),'.','Color',[0 0 0],'LineWidth',0.3); 
           text(pt_I(1)+txt_pts_offset(idx_L,1),pt_I(2),'$I$',...
                 'Interpreter',"latex",'Color',[0 0 0],'FontSize',8);
     
    % Plot final point
    pt_F = [[manif_traj(end).x]*au2km,[manif_traj(end).y]*au2km];
           plot(pt_F(1),pt_F(2),'.','Color',[0 0 0],'LineWidth',0.3); 
           text(pt_F(1)+txt_pts_offset(idx_L,2),pt_F(2),'$F$',...
                    'Interpreter',"latex",'Color',[0 0 0],'FontSize',8);
end
hold off

% Axes lables
xlabel('$x$ (km)','interpreter','latex','fontsize',12);
ylabel('$y$ (km)','interpreter','latex','FontSize',12);
ax=gca;
%Legend 
lgd = legend([traj_plot,CI_plot],'Orientation',"vertical",'Location',"northeast");
lgd.Interpreter = 'latex'; 
lgd.FontSize    = 8;

% Extra information box
dim = [0.23 0.815 .150 .06];
str = ['$Epoch_I = t_0 $',newline,...
       '$Epoch_F = t_0\ + \Delta_{t\ CI} $'];
an=annotation('textbox',dim,'String',str,'Interpreter',"latex",'FitBoxToText','on',...
           'BackgroundColor',[1 1 1],'FontSize',8,...
          'HorizontalAlignment','left','VerticalAlignment','bottom');

%% Calculate the required margins
newx = ax.InnerPosition(1)+ax.InnerPosition(3)-(lgd.Position(1)+lgd.Position(3))+ax.InnerPosition(1);
newy = lgd.Position(2)+lgd.Position(4)-an.Position(4);
set(an,'Position',[newx newy an.Position(3) an.Position(4)]);

% Option to center better the curves inside the plot window
x_lim = xlim; y_lim = ylim;
xlim([x_lim(1)-0.005*norm(x_lim) x_lim(2)+0.005*norm(x_lim)]);
ylim([y_lim(1)-0.1*norm(y_lim) y_lim(2)+0.3*norm(y_lim)]);

JC_id   = ['$JC\ index =\ $',num2str([UHIM_DB(idx_L).data(idx_JC).idx_Jacobi_cst])];
traj_index = ['$traj.\ index =\ $',num2str(idx_manif_traj)];
title([JC_id,', ',traj_index],'Interpreter','latex');

%set(gcf,'position',[400, 200, 560, 315]);  %Aspect ratio: 16/9
set(gcf,'position',[278.6, 0.2, 600, 400]);  %aspect ratio 3/2

%exportgraphics(fig,'fig_UHIM_test.pdf','ContentType','vector'); %salva in pdf
%exportgraphics(fig,'fig_UHIM_test.png','Resolution',600); %salva in jpeg

If you try to export the figure, you can see that the horizontal alignment of the annotation box is wrong.

My output is shown below (You can see more details that I removed from the above code to simplify it):