how to set the figure width

I am trying to create a figure of width and height of 3 inches from an existing saved figure. How can I do this?

I would like to save this figure as a .png of the same size. Can I save this as png of this (3x3 inches) size.

I have also noticed that some parts of the labels disappears when saving it to .png. Why is this so? How do I prevent this?

Many thanks,

Answer 1

[Azzi Abdelmalek]

figure
set(gcf,'paperunits','inches')
set(gcf,'position',[0 0 3 3])
saveas(gcf,'fig1.png')

[Lizan]

How do I fetch the figure name so I will change this to an existing figure of my choice?

[Azzi Abdelmalek]

What do you mean?

[Azzi Abdelmalek]

name='fig_choice.png'
saveas(gcf,name)