can I disable entire sections of code temporarily

Can I disable entire sections of code temporarily?

I have a large code that contains different scenarios. I'm working on one scenario and I'd like to disable the other sections, just while I'm working on that bit so that I can run the code quickly without having to wait for it to do all the other stuff too.

[Matt Fig]

Tom's question

Can I disable entire sections of code temporarily?

I have a large code that contains different scenarios. I'm working on one scenario and I'd like to disable the other sections, just while I'm working on that bit so that I can run the code quickly without having to wait for it to do all the other stuff too.

[Giovanni Guerrero]

comment out the lines using (hold) ctrl then R then undo this by (hold) ctrl then T

[Kabilan Nedunchezian]

Hi,

Use commenting in a smart way!

the following will not be executed in your code

%{
        x = ('this will not be executed')
%}

to make it executable just remove the first curly bracket to make it executable

%

          x = ('this will be executed') 
%}

[Robert Daly]

Kabilan, this tip is gold! Thanks.

Answer 1

[kfir]

You can mark this whole part and Ctrl+R. you can also work in cell mode, and run only the cells you want.

[Tom]

Sorry, but I didn't understand that answer. I tried selecting an area of the code and pressing Ctrl+R and nothing happened. I haven't come across cell mode before.

[kfir]

try looking in the "text" menu. Ctrl+R appears there.

Cell mode is a very nice tool, from Matlab 7 and above.

I also liked the answer given by Daniel. Very simple, and you can unfold all the "if" statement.

[Miguel Ordoñez]

Does anyone know if there is a command similar to Ctrl + R for Mac OS? Thanks

[Mung Suan Pau DUHLIAN]

• Select the code/s you want to temporarily disable ( or comment) and press (Command and / )
• To undo the disable (or discomment ) select the code/s and press (Command and T)
• Hope this is relevant:).

[Chi-Chao]

I'm on online matlab in chrome with MacOS. Cmd+T will just open a new tab in chrome. Is there other way around it?

[DGM]

You should normally be able to open preferences>keyboard>shortcuts and set them as needed. I don't know if that works on MATLAB Online.

[Steven Lord]

In MATLAB Online you're not able to customize keyboard shortcuts AFAIK, but hovering over the comment button in the Code section of the Editor tab in the toolstrip says that Ctrl+R is the shortcut to comment out the selected lines in the Editor. Ctrl+Shift+R is the command to un-comment.

But yes, if you're using Desktop MATLAB you can customize the keyboard shortcuts and make Comment whatever you want (within reason; if you were on Windows, I believe it handles Ctrl+Alt+Delete on its own before that reaches any application so you can't use that as your shortcut.)

Answer 2

[Daniel Shub]

You can enclose code in an if block

if false
  ...
end

or even better (since you can include invalid syntax) would be to use block comments

%{
  ...
%}

The nice thing with block comments is that you can comment the comment

%%{
  ...
%}

to reactivate the code. The only thing to be careful with is if you auto indent and/or autowrap the code in the block comment your line breaks can get screwed up.

Answer 3

[Jason Ross]

Usually when I get to a place where the code has gotten this large, a little voice in my head starts screaming "PUT IT IN A FUNCTION" (or subroutine, or module, or whatever means the language I'm coding in has to compartmentalize a section of code). That way I can separate the overall program flow from the detailed bit of what each step of the program is doing. And then it becomes simple to control that flow with a comment or other conditional method.