A lot of the code that I write in Matlab has a very verbose output. As the program runs, information is printed to the command window, and with each new line, the window automatically scrolls to the bottom. This becomes a problem when I want to read some of the output more closely or scroll up to look at older output. I can scroll up, but only until a new line is printed, which is often less than a second.
Does anyone know if it is possible to turn off this automatic scrolling in the Matlab window? I work in a number of different Matlab versions, depending on the machine, and this happens with all of them. The answer to this might be "No", but I swear I remember having this functionality at one point.
Use the more function: http://www.mathworks.com/help/matlab/ref/more.html
more on
Then run your program. Press spacebar when you wish to see more of the output.
more off will turn it off.
You may find this workaround useful.
First launch matlab using the command line matlab -logfile 'myLog.txt' (the doc says it "starts MATLAB and makes a copy of any output to the Command Window in filename. This includes all crash reports.")
Then open your .txt file using a text editor supporting automatic refresh of content (see picture). On OSX I use TextWrangler (freely available at www) but others have been reported to have this feature (see here or here).
Results: output displays (fprintf, disp, but not the commands per se) are printed both on the Matlab console and the text editor (file is refreshed with a little lag time, below half a second I would say with my configuration). And there is no automatic scrolling. Such procedure does not seem to impact the overall performance of the script (although it may deserve some testing).
Related
IPython 5 is a big release. One of its features is real multi-line editing with prompt_toolkit. The up arrow key now moves to the previous input line instead of the previous input command (block of lines).
This is awesome, but when my previous command spans many lines, and I need to reach the command before that, I find myself wishing I could go up one command at a time. Is there a way to do that? The shortcut ctrlp has the exact same behaviour as the up arrow key, so it does not provide a solution.
On my own Belgian Mac keyboard, fnshift↑ does the job. But I cannot tell whether this also works for other locales.
The PageUp and PageDown keys do exactly what you want without any chorded hotkeys involved; they work on an entry-oriented basis, rather than the arrow keys' line oriented approach.
I did a standalone application in Matlab and it works. The only problem is that when I launch the application, it takes time before start asking to the user some file (it is the first think the program has to do). The user does not understand if the program is working or not, since no message neither symbol of working progress appear on the screen.
My idea is to show a waitbar until the window asking the file to user appears.
How can I do this? is it possible to use the waitbar outside a loop?
The script starts as follow:
close all
clear all
[filename,pathname] = uigetfile({'*.xlsx'},'Opening File','C:\');
I don't know why, it takes time before open the window for choosing the file.
The time between launch and file selection input appearing is most likely due to the time it takes to load the MCR. You could add a splash screen to your compilation.
If the end user is running from a command line wrap your exe in a system/shell which writes to the command window that the application is starting.
Your issue is most likely the use of clear all. This makes MATLAB remove all variables (in scope, global and persistent), and compiled scripts from memory, forcing it to recompile and load everything again.
If your purpose is to clear all variables in the current scope, you should be able to increase the initial speed of your script by only running clear instead.
Even faster speed can be achieved if you specify which variables to clear using clear var1 var2 ...
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.
I was checking the original 'clc.m' file in MATLAB. Apparently the function is written as a p-code and you just see the description which is placed in:
..\MATLAB\R2013a\toolbox\matlab\iofun\clc.m
How can I take a look at the original code?; however this is not the main question, it is just for fun.
The main point is I am looking for a way to reverse the clc process, after you clean the screen. Is there any way to reverse the clc process. The same question goes for clear all as well.
Try using home instead of clc. Whereas clc removes all text from the Command Window and moves the cursor to the top left giving you a blank window, home just moves the cursor to the top left and gives a you a blank window - but the text is still there, and you can scroll up to see it. I use home all the time rather than clc.
In either case, the text remains in the Command History window, and can be retrieved in the Command Window using the Up/Down arrows.
The reason you can't see the code behind clc is not that it's p-coded, it's that it's a built-in function (i.e. not implemented in the MATLAB language). The same is true for clear, and also many math functions such as svd, eig etc. There's no way to modify them to change what they do (such as reversing the process).
Edit: You might also like to look into the diary function, which keeps a log of all the input and output at the command window in a specified file. I have the following lines in my startup.m file (type doc startup if you don't know how to use MATLAB startup files):
diaryFolder = 'C:\diaries';
diaryFileName = ['diary', datestr(now, 'yyyymmdd'), '.txt'];
diary(fullfile(diaryFolder, diaryFileName))
So whenever I start MATLAB, it's automatically capturing all command window input and output to a diary file that's named by the date - If I start MATLAB multiple times a day, it just appends to the same file. I can clc or home whenever convenient, and there's always a record kept of everything that I can search through if necessary.
I don't believe there would be anyway to undo the clc process. That said, it is possible to still view the command history, so that might get you somewhere.
Once you clear the data, I believe it's gone forever. I highly doubt that data is stored in memory somewhere. I know that after a certain number of lines, the history is deleted. So your best bet is to start figuring out how large that buffer is and proceed from there to see if you can find anything interesting.
I am using run-octave in Emacs to trigger octave. Something is acting abnormally.
Every time I hit TAB to complete, there would be a tailing ^M; If I edit a .m file using edit a.m, it would start a new frame instead of a new buffer and the prompt is waiting for the closure of that frame so it would not respond to any input. How could I configure .emacs so that run-octave would behave normally?
Any comment is appreciated!
You seem to have two problems. I'm not sure about the trailing ^M, which seems to be caused by some sort of Windows/Unix CR/LF problem, but maybe I can help with the second problem.
The edit command uses the EDITOR environment variable to decide what to run. It seems that yours is either set to emacsclient or has defaulted to it. You haven't said whether you're on Unix or Windows, so I'm going to assume the former: you'll have to change this a bit for Windows.
To avoid the waiting thing, try running octave with a different EDITOR. For example, try out running
EDITOR='emacsclient -n' octave
When you type edit foo, it should bring up an Emacs buffer (if you want a new frame as well, use -c too) but not wait until you're done.
If this fixes things for you, you could change your ~/.bashrc to include the line
export EDITOR='emacsclient -n'