Matlab-generated PDF graph
If you have saved your Matlab-created graph as a pdf file, then you can use it in your Latex document using:
You may change the size of your figure by tuning the options inside the braces to fit it to your space. Then compile your whole document:
pdflatex -interaction=nonstopmode -src main.tex
Matlab-generated EPS graph
If you have saved your Matlab-created graph as an eps file, then the same procedure applies for including the figure. For compilation use:
latex -interaction=nonstopmode -src main.pdf
If you are creating a presentation using beamer class, see beamer's documentation, chapter Creating PostScripts.