How to keep the aspect ratio fixed when putting legend outside of plot

As the title suggests, the ratio of the plot changes when putting a legend outside. For instance, placing the legend inside:

clear all, close all

x = 1:10;
y1 = 4*x;
y2 = 3*x + 5;
figure(1), plot(x,y1,'b',x,y2,'r')
legend('Line 1','Line 2')

Compare that with placing the legend outside:

legend('Line 1','Line 2','Location','NorthEastOutside')

Evidently, the ratio changes. Please provide suggestions if you know how to solve this problem. Your help is kindly appreciated.

Answer 1

[Daniele la Cecilia]

x = 1:10; y1 = 4*x; y2 = 3*x + 5; figure(1), plot(x,y1,'b',x,y2,'r'), axP = get(gca,'Position'); legend('Line 1','Line 2','Location','NorthEastOutside'), set(gca, 'Position', axP)

[András Pálffy]

elegant, thanks!

[Mikail Cöloglu]

thanks !

Answer 2

[gaurav srivastava]

 % %The problem can be solved by following below steps. This keeps plot area size constant:
% set unit for figure size to inches
set(gcf, 'unit', 'inches');
% get the original size of figure before the legends are added
figure_size =  get(gcf, 'position')
% add legends and get its handle
h_legend = legend('legend1', 'legend)
set(h_legend, 'location', 'northeastoutside')
% set unit for legend size to inches
set(h_legend, 'unit', 'inches')
% get legend size
legend_size = get(h_legend, 'position')
% new figure width
figure_size(3) = figure_size(3) + legend_size(3)
% set new figure size
set(gcf, 'position', figure_size)

[li weilin]

Thanks! This is what I want!

[Sim]

Hi, I got a similar problem when I had to put a legend - with variable size - outside the plot.

In my case, I had many figures with a variable legend size, for each figure.

My goal was to keep the plot size constant in each figure and just changing the legend size (in particular the width, through the number of columns).

I found that the Azzi Abdelmalek's solution worked for my case (i.e. keeping the plot axes size and position constant for all my figures), while I found that the Gaurav Srivastava's solution did not work for my case.

You can check both solution by changing the

h.NumColumns 

from 1 to 4, to see the differences between the two proposed solution. Here following the code I used:

% input data
x = 1:10;
y1 = 4*x;
y2 = 3*x + 5;
y3 = 2*x - 2;
y4 = 3*x.^2;

% Gaurav Srivastava's solution
figure('position',[10 10 1300 500],'Color',[1 1 1]);
plot(x,y1,'b',x,y2,'r',x,y3,'m',x,y4,'g')
set(gcf,'unit','inches');
figure_size = get(gcf,'position');
h = legend('legendfsdjfsdofodfodfosydfdfysdfidyfdhfdfhfldfhfjfhd1',....
    'fjsdjfsdfjdjfdjsfhjdfhfsdhfhsdfsdhfosfhsohfjdfhjf',...
    'qqqqqqqqQQQQQQOPPPPOQPOPQOPOQPOQPOQPOQPOQPOPQOQPQOPQOQPOPQO',...
    'legendfffffdfsddfdfdfsffffsdfbnsdbfnsdbfnmsbfnffdfdf');
h.NumColumns = 4;
set(h, 'location', 'northeastoutside')
set(h, 'unit', 'inches')
legend_size = get(h, 'position');
figure_size(3) = figure_size(3) + legend_size(3);
set(gcf, 'position', figure_size)


% Azzi Abdelmalek's solution
figure('position',[10 10 1300 500],'Color',[1 1 1]);
plot(x,y1,'b',x,y2,'r',x,y3,'m',x,y4,'g')
h = legend('legendfsdjfsdofodfodfosydfdfysdfidyfdhfdfhfldfhfjfhd1',....
    'fjsdjfsdfjdjfdjsfhjdfhfsdhfhsdfsdhfosfhsohfjdfhjf',...
    'qqqqqqqqQQQQQQOPPPPOQPOPQOPOQPOQPOQPOQPOQPOPQOQPQOPQOQPOPQO',...
    'legendfffffdfsddfdfdfsffffsdfbnsdbfnsdbfnmsbfnffdfdf');
h.NumColumns = 4;
set(h, 'location', 'northeastoutside');
set(gca,'position',[0.1 0.1 0.2 0.8])

[Gareth Davies]

Why do you set the unit size to inches (or indeed to anything)? Does that do something important that not obvious?

[FWDekker]

@Gareth Davies tl;dr: You want to make sure you're not mixing units.

Long version: (1) You want to make sure the figure and the legend use the same units, or else you'll be adding inches to centimetres without appropriate conversion. (2) By default the unit for the legend is 'normalized', which is its size relative to the entire figure expressed as a fraction. So if the legend h takes up 30% of the width of the figure, then h.Position(3) will equal 0.3. Meanwhile, for the figure, setting the units to 'normalized' will mean that its size is relative to your desktop resolution. In other words, even if the figure and legend both use 'normalized' as units, the units are incomparable.

Answer 3

[Azzi Abdelmalek]

legend('Line 1','Line 2','Location','best')

[Gunnar]

Dear Azzi, thank you for your reply. Unfortunately, it does not really answer my question. Your proposal may or may not place the legend inside the plot. Even if it is placed outside, the aspect ratio will, if I'm not mistaken, still change.

[Azzi Abdelmalek]

I thought you are looking for the best place to your legend. But if you insist to place it outside the figure, that means some part of the figure will be reserved to your legend. I am not sure to understand what solution you want.

[Gunnar]

The example code in my initial post was only meant to serve as a simple example. In reality, I have a plot that is full of data, and by putting the legend inside, parts of the data will be made "invisible".

On the other hand, putting it outside will change the ratio of the true plot and skew its appearance.

[Azzi Abdelmalek]

That's why I suggested the 'location','best'. The legend will be placed with least conflict with data in plot.

If you want to place it outside the plot, you can change the size of your plot:

plot(x,y1,'b',x,y2,'r')
h=legend('Line 1','Line 2','Location','NorthEastOutside')
set(gca,'position',[0.1 0.1 0.8 0.8])