How can I run Matlab .m file repetitive in background? - matlab

I have project that was wrote in MATLAB. It has Main file like Main.m, I want to run Main.m repetitive every 1 Second in background.
I don't want to see any display and opening windows from MATLAB.
How can I do this ?

There are two steps to achieve this. First write some m script which calls your Main function every 1s. You can use a loop like this one. Getting the time via toc is important in case your main function takes some time to compute. An alternative are timers, which avoid any time drift (The loop is typically slightly above 1s, the timer will be 1s on average).
Once your MATLAB knows what to do, the question is who to start it. There is the -batch option:
Execute MATLAB script, statement, or function non-interactively.
MATLAB:
Starts without the desktop
Does not display the splash screen
Executes statement
Disables changes to preferences
Disables toolbox caching
Logs text to stdout and stderr
Does not display dialog boxes
Exits automatically with exit code 0 if script executes successfully.
Otherwise, MATLAB terminates with a non-zero exit code.
statement is MATLAB code enclosed in double quotation marks. If
statement is the name of a MATLAB function or script, do not specify
the file extension. Any required file must be on the MATLAB search
path or in the startup folder.
Use the -batch option in non-interactive scripting or command line
work flows. Do not use this option with the -r option.
To test if a session of MATLAB is running in batch mode, call the
batchStartupOptionUsed function.
Example: -batch "myscript"
This means MATLAB will not open any window, instead you see any output in the calling command line. How it looks on LINUX:
x#y ~ $ matlab -batch "1+1"
ans =
2

Assuming there is a top-level function in Main.m that you would like to execute once every 1 second, one possibility is to start an instance of Matlab and create another script that calls your function in a forever loop with a 1 second pause (making sure that this other script has Main.m file in the PATH so it can see it)
function run_main_forever()
while true
my_function()
pause(1)
end
end
You can have a .bat file start matlab in the background and run the script like this:
matlab -nodesktop -nosplash -r "cd('C:\Path\To\'); run_main_forever();"
See this link for further details on launching MATLAB without the desktop: https://blogs.mathworks.com/community/2010/02/22/launching-matlab-without-the-desktop/

Related

MATLAB System Command "Press Enter to Exit"

I am trying to write a MATLAB script that would call and run an external program and then proceed with other MATLAB commands.
tic %Start stopwatch
system('MyProgram.exe') %Call and run my program
toc %End stopwatch
However, this program "MyProgram.exe" requires me to "Press Enter to Exit." How to make my MATLAB script pass "Enter" to proceed? Like How to pass "Enter" as an input of my program at the end of execution? Or how to do this in general ?
On UNIX, you can use
system('MyProgram < /dev/null').
as suggested in the Matlab documentation:
To disable stdin and type-ahead redirection, include the formatted
text < /dev/null in the call to the invoked command.
The Windows equivalent is (based on this post):
system('MyProgram.exe < NUL')
When a console program needs to take input one time from the user and there is no built-in way to do so (like passing it in as an argument), that input can be echoed and piped to the program. This can also be used to press Enter (again, once) by piping a blank line.
echo.|program.exe
While traditionally a blank line is generated with echo by using the command echo., this can fail if the current directory contains a file called echo that has no extension. To get around this, you can use a ( instead of a ..
echo(|program.exe

Alternatives to `clear(function_name)` to remove function from RAM?

As stated in MATLAB's FAQ,
1.3.3.1. Why, when I edit a function file in MATLAB, is the change not seen by MATLAB until everything is cleared or MATLAB is restarted?
When you write an M-file in MATLAB, you can either write a script or a
function. The difference is that a script is read from the disk and
parsed line by line each time it is called. A function is loaded into
RAM for execution. Because it is loaded into RAM, when you edit a
function, that change is not loaded into RAM until a call to the new
function is made.
To get MATLAB to recognize your edited function, type
clear functions to clear all functions, or
clear <function name> to clear just your function out of RAM.
This is a major pain when I'm developing a function & editing it repeatedly (I use an external editor most of the time). I was thinking of putting in a final line, at least during debug, like
clear(myfunc)
but I'm concerned about unwanted side effects. Does anyone know if there are any?
Further, I'd rather have a way to configure MATLAB so it doesn't automatically store called functions in RAM once the top-level function (i.e. the one called from the console) terminates. Is that even possible?
EDIT: I should mention that MATLAB's behavior is inconsistent. Sometimes my edits take effect once I save the m-file, other times they don't even if I'm editing with the MATLAB IDE editor window.
In all honesty MATLAB has a very powerful editor so you really should
be using it. It will make you life easier. (just an opinion)
Unless you are running the code by stepping through it no change to code will be run until the code is re-run (preferably with a cleared workspace).
clear(myfunc) will clear the variables created by that function in upto that point. You can add at the end of any function or script clear variableA variableB for all variables you want cleared at the end. This will give you control to only clear what you want. Once variables are cleared the only effect will be that if those variables are called again later in the code an error will occur since they no longer exist.
If your simply testing that particular function and want to save time by not calling inputs each time and want to clear the workspace and command window at the same time. You can add the following code just beneath the function definition.
If you leave the following code and call the function from another function or script, the code will be ignored as long as the inputs are available to it externally. Anything you add to the if statement will only occur when you call the function with no inputs doc nargin. You could add it to the top level function and you would simply press the run button or f5 without having to type in the command window to run the code.
function [ output1, output2 ] = blah( input1, input2 )
if nargin == 0
clc
clear all
%above two lines will clear the workspace and command window when you run
%the function
%define function inputs
%(optionally add the following to behave as if you inserted a breakpoint
%in the location just before the error occurred (great for debugging)
db stop if error
end
*you can also add a short-cut to snippets of code up in the top right of the MATLAB interface to clear the workspace etc when they are clicked.
Hackish* idea for this:
I'd rather have a way to configure MATLAB so it doesn't automatically store called functions in RAM once the top-level function (i.e. the one called from the console) terminates. Is that even possible?
* This is the sort of thing I might use, while advising others on why it is a bad idea, also probably uses undocumented (thus unreliable) things.
Specifically if your using an external editor I guess your going to have to click on the command window to run the function...
commandWindowHandle = ...
handle(com.mathworks.mde.desk.MLDesktop.getInstance.getClient('Command Window'...
.getComponent(0).getComponent(0).getComponent(0),'CallbackProperties');
commandWindowHandle.MouseClickedCallback = 'clear functions'
It doesn't clear the function definitions on exiting a function rather on clicking on the command window
note: the callback will not fire if a function is currently running
For a potentially more reliable but more wasteful version:
commandWindowHandle.KeyPressedCallback= 'clear functions'
will help* ensure definitions are clear, but is wasteful as every keystroke will run 'clear functions'... although after one keystroke this will be quicker as there will be no functions in memory!
* No guarantee I know there are ways in which this could fail... having at least 1 keystroke in the command window after the previous function call has finished would be advisable!
To disable these set the callback to empty string ''
commandWindowHandle.MouseClickedCallback = ''
commandWindowHandle.KeyPressedCallback= ''

Close all figures when a script is running in Matlab

Assume that a script is running in Matlab. Is there any way to close all figures? (Closing each figure individually is tedious, and since the script is running I cannot add close all to it.)
I recommend to run such scripts using a command line version of matlab, including the option -noFigureWindows. If you want to run it in a full matlab UI (which is slower), use a timer object:
t = timer('TimerFcn',#(x,y)(close('all')), 'Period', 10.0);
start(t)
Don't forget to close and delete the timer after finishing your script.
This works for me (tested in R2010b): in Matlab's command prompt, go to the menu bar, select Windows, then Close All Documents. This closes all figures, as well as editor files, while an m-file is running.

How to return to prompt after running an exe file compiled with mcc (Matlab compiler)

I have an executable created with mcc. The .m file has a simple function that reads and plots values. After I run it from DOS, it freeze without returning execution to DOS. 2 questions:
1) How can i return execution to dos? I tried "return" and "exit" commands but didnt help
2) How to close the dos windows? is the only way to use a batch file or can I do it with a command in the .m file?
thanks
A.
There are 2 scenarii:
If your run your matlab executable from a DOS window, the DOS window will not get control back until the program terminates. If the program generate matlab figures (plot, surf, etc...), the program will not return to the console until all of the figures are closed.
You may think it is a waste for a simple plot, but after all your figure could be a evolved gui with a lot of code to execute. Or even a simple figure with a closeRequestFcn. So in Matlab terms, your program may still have instructions to execute as long as a figure is opened, so it will not return until it sure there is nothing more to do.
If you simply double clicked on your executable, the DOS looking console which open with your program will have the same behaviour. It will not disappear until the program returns (so until all your figures are closed if relevant).
I am not sure about linux, versions, but if you are running on windows, there is a way to suppress the DOS looking console for your graphic applications. Look at the -e switch in the mcc options.
This switch will compile your program in a way that no DOS console is opened when you double click on your executable.
So to summarize, I would recommend:
If your program is a 'command line' type (a function that takes input from the console and return values to the same). => Compile with normal options, and execute it from a DOS window (you do not want the window to disapear as soon as the program terminates.)
If your program is a gui or even simple plotting functions, with no need for console interactions, then compile with the -e switch and execute it by double clicking the .exe file.
note that in case you use the -e switch, it is recommended to direct potential output to a logfile. Look at the mcc documentation for more info.
edit
If you really need the DOS console and some graphic output, run your program form the command window with the following syntax:
start /b YourProgram
This will start the program in "background mode" (use YourProgram & in Linux terminal). You will be able to do anything in this console window, and you will also see the output from your matlab executable.
It can be confusing because the output from your program will be added to the simple dos prompt and you may think you do not have the control but if you type any command it will work. You can even start many program this way and retain control in your console, but all the output will arrive in the same window and they may be difficult to differentiate.

Can you pause MATLAB? [duplicate]

This question already has answers here:
Stop and continue execution from debugger possible?
(6 answers)
Closed 6 years ago.
In MATLAB, I'm running some code which takes a while to run. I'd like to pause the code to check on some variable values. Is there a way I can do this without having to re-run the code from the beginning? I don't want to terminate the program; just pause it.
You can halt execution and give a command prompt in two ways of which I am aware:
Putting keyboard in your code where you want to stop.
Setting a breakpoint.
You can resume and stop execution with dbcont and dbquit, respectively. To step forward, use dbstep. dbstack lets you see where you are. There are many more commands. The help page for any of these will give you other suggestions.
As Dennis Jaheruddin has pointed out, dbstop also has several useful features worth trying. In particular is the ability to set conditional and global (any line meeting a criterion) breakpoints via the dbstop if syntax. For example, dbstop if error will break to a debugging command prompt on any error. One suggestion he made, which I now do, is to put dbstop if error into startup.m so that this behavior will be default when you start MATLAB. You may need to create this file in a userpath folder; edit(fullfile(regexp(userpath,'^[^;]*','match','once'),'startup.m')).
One way to achieve what you're looking for would be to use code sections (also known as code cells), where you divide your code into sections divided by lines with two percent signs (%%).
Then, in the editor, you can press ctrl+enter to execute the current code section, and ctrl+up/down to navigate between sections.
Well there is the pause command, but then you cannot check for the variable contents in the workspace because the program is running.
What you probably want is to set a breakpoint (See the Debug menu / key F12).
At a breakpoint matlab pauses the program and enters debugging mode in which you can see and edit the variables. Once finished, you can resume the program where it was paused.
I'm not sure about Windows users but if you're running Linux you can start Matlab in a terminal using
matlab -nodesktop
then once Matlab has started, cd to your project directory and start your Matlab script. Now whenever you want to pause execution you can use ctrl-Z. Then to resume type fg. I hope this helps.