how to run the matlab code step-by-step?

Dear sir/madam,

I need to run the matlab code step-by-step, and also see what is happening in the code or the variables. How can I do this? Looking forward to hearing from you soon.

Thanking you, BSD

Answer 1

[Arnaud Miege]

Use the debugger. See Editing and Debugging MATLAB Code in the documentation for more details.

HTH,

Arnaud

[Jan]

@Arnaud: Thanks for this important answer. Although it might seem so obvious, there are a lot of questions in this forum, which could be avoided, if the user knows how to apply the debugger. +1

Answer 2

[Andreas Goser]

Many users also prefer not line by line, but a bit larger chunks. Look for "Cell Mode".

[bsd]

@Andreas Goser,

Thanks for the reply. What is this cell mode? I a new to matlab. Please brief it.

Thanking you,

BSD

[Jessica]

@bsd, If you put %% on a line, you'll notice that it separates the code into pieces. You can separate chunks of your code by putting %% in various places. Then, if you want to just run one cell, you can simply hit ctrl+enter (or right click and then click "Evaluate Current Cell").

Ex:

%% First cell
x = 1:2:10 ;
y = 5:-1:1 ;
z = x + y ;
%% Second cell
figure(1)
plot3(x,y,z)

When you ctrl+enter while your cursor is in the first cell, it only defines the variables. Then, when you ctrl+enter while in the second cell, it only plots the figure. I hope that helps clarify @Andreas Goser's answer.

[Arnaud Miege]

If you read the section of the documentation I mentioned in my answer, you'll see there is a part entitled "Evaluating Subsections of Files Using Code Cells".

Answer 3

[Daniel Shub]

There is a recent blog post by Loren http://blogs.mathworks.com/loren/2011/04/28/is-there-an-echo-out-there/ about the echo command. Cell mode and the debugger are nice, but I think a lot of us have forgotten (or never knew) the power of echo.