Ffigure saved as pdf: how to get proper control of margins

Hello,

I want to save a figure as a pdf, and would like to get control on the margins around the figure in the pdf.

Here is an example :

load('test_0.mat'); % contains the variables AudioSnip, frameSize, Hop , fs

s_length = length(AudioSnip);

nframes = 1 + floor((s_length - frameSize)/double(Hop ));

UsableSigLength = frameSize + floor(Hop *floor((s_length - frameSize)/double(Hop )));

sampleTime = ( 1: UsableSigLength )/fs;

%$$$$$$$$$$$$$$$$$$$

[B,f,T] = specgram(AudioSnip,frameSize*2,fs,hanning(frameSize), Hop); %(1: UsableSigLength)

B = 20*log10(abs(B));

%

TheFig = figure;

h = gcf ; %gcf returns the current figure handle

h.Units = 'centimeters';

h.PaperType= 'A4';

h.PaperUnits = 'centimeters';

h.PaperOrientation= 'landscape'; % 'portrait';

h.PaperPositionMode= 'auto';

h.InvertHardcopy = 'on';

h.Renderer = 'painter';

margin = 4.; width = 29.7; height = 21.;

h.Position = [margin margin width-2*margin height-2*margin];

h.PaperSize = [29.7 21.0]; %[21.0000 29.7000];

subplot(2,1,1);

plot(sampleTime, AudioSnip(1: UsableSigLength));

xlabel('Time (s)','FontSize', 10, 'FontName' ,'Times', 'FontWeight', 'bold');

ylabel('Amplitude', 'FontSize', 12, 'FontName' ,'Times', 'FontWeight', 'bold');

set(get(gca, 'xlabel'), 'Position', [ 21.,-0.21,-1]);

h1 = gcf;

h1.Units = 'centimeters';

atx1= gca; % axes 'Position', % xtart, ystart xend yend coord

atx1.Position = [0.1300 0.7099 0.6949 0.1635]; %

atx1.FontSize = 10 ; atx1.FontName = 'Times'; atx1.FontWeight = 'bold';

atx1.Units='normalized';

Tt0=text('Units','normalized','Position',[ 0.0009 1.4599 0 ],...

'VerticalAlignment', 'Bottom', 'FontName', 'Times', 'FontSize',14 , 'FontWeight', 'bold', 'String', 'text1');

Tt1=text('Units','normalized','Position',[ 0.0009 1.260, 0 ],...

'VerticalAlignment', 'Bottom', 'FontName', 'Times', 'FontSize',14 , 'FontWeight', 'bold', 'FontAngle', 'italic','String', 'text2');

Tt2=text('Units','normalized','Position',[0.0009 1.0509 0],...

'VerticalAlignment', 'Bottom', 'FontName', 'Times', 'FontSize',12 , 'FontWeight', 'bold', 'String', 'text3');

subplot(2,1,2);

h2 = gcf;

h2.Units = 'centimeters';

atx2= gca; % axes('Position', % xtart, ystart xend yend coord

atx2.FontSize = 10; atx2.FontName= 'Times' ; atx2.FontWeight = 'bold';

atx2.Units='normalized';

atx2.Position = [0.1300 0.0720 0.7334 0.5965 ];

imagesc(T,f,B);axis xy;colorbar;

ylabel('Frequency (Hz)','FontSize', 12, 'FontName' ,'Times', 'FontWeight', 'bold');

xlabel('','FontSize', 12, 'FontName' ,'Times', 'FontWeight', 'bold');

colormap jet

exportgraphics(TheFig, 'outputTest.pdf');

When I run it,

A) I do not get a proper control on the margins around the figure: the parameter 'margin' (see code)does not seem to affect the result in the pdf obtained

What should be done ?

Miscellaneaous other problems:

B) I would like to align the time corresponding to the end of the data (first subplot), with the end of the spectrogram data (2nd subplot): how should this be done ? (I tried some adjustment via axis position, but the colorbar is also messing things up)

C) the font for the 2nd subplot is not the expected 'Times'; (I tested that it is indeed possible to manually force 'Times' using the figure inspector, but not by the program line above (atx2.FontName = 'Times')

why ? how to enforce 'Times' by programing ?

Answer 1

[Rahul]

Hi @francois heslot,

I understand that you wish to make various modifications to how the figure is being saved as a pdf. You can consider the following changes:

1. To control the margins around the figure in pdf:

• From MATLAB R2024a onwards, various properties like 'Padding', 'Width', 'Height', 'PreservedAspectRatio' are available with the 'exportgraphics' function. Hence upgrading to a MATLAB version from R2024a onwards would enable in setting the required margins around the figure.

• The 'print' function can also be used instead of 'exportgraphics'. This function requires a figure object, and the properties of the figure like 'PaperSize', 'PaperPosition' etc. can be set accordingly.

2. Align Time Axis of subplots

• You can use the 'linkaxes' function to align the axis of both subplots.
• The 'Location' property of 'colorbar' can be used to align it properly to not interfere with the axis.
• The 'titledlayout' function may also be useful in this case.

3. Set font for a particular plot

• The fonts for Labels and colorbar can be set individually using their 'FontName' property. Here is an example:

set(atx2, 'FontName', 'Times');
atx2.XLabel.FontName = 'Times';
atx2.YLabel.FontName = 'Times';

c = colorbar;
c.FontName = 'Times';

The following MathWorks documentations can be referred to know more:

'exportgraphics': https://www.mathworks.com/help/matlab/ref/exportgraphics.html

'print': https://www.mathworks.com/help/matlab/ref/print.html

'linkaxes': https://www.mathworks.com/help/matlab/ref/linkaxes.html

'colorbar': https://www.mathworks.com/help/matlab/ref/colorbar.html

'titledlayout': https://www.mathworks.com/help/matlab/ref/tiledlayout.html

Thanks.