Yair, If I was wearing a hat, I would have taken it off in your honour! This is an impressive demonstration of obsession, detective work and development.

WOW!! I am sure that a lot of people will download your utility, it is such a common request from worldwide MATLAB users!
You are a guru !!

Great!
Is there anyway to control the text displayed in the Editor? For example to display Greak symbols in the comments using LATEX?

@Junziang – as far as I know you can only use LATEX in plot texts, not the editor/CW

Thanks Yair!

I think with the same method used in your cprintf, not only the color but the font(font name/font style….) can also be readily changed. So I hope with the next version of cprintf we can also change the font of the text in the CW.

I like cprintf! Thanks a lot!

@junziyang – that’s an interesting suggestion – I may indeed try this 🙂

From the cprintf syntax example I might guess that each call adds text to the current buffer using one unique 2-parameter style (color and underlined/link). Besides the question whether it is technically possible to switch also the FontName, FontSize, FontWeight etc for each new token before the buffer is terminated and we see the >> prompt again, I am curious if we will ever see some hprintf for HTML-formatted text, to specify text with changing properties using one single command? Yair, would that be an option for cprintf version 2.0?

However, don’t feel stressed!-) What you gave us is already cool enough and deeply impressive. After all, my very personal approach is to use the command window only to display plain text, because everything else is (was?) so much easier to display with GUI elements (which already *can* interpret basic HTML in their String property). But from a sportsman’s viewpoint… wow, you are miles ahead!

[…] to enable display of text in any color, as well as underline, in the Command Window. See my post on cprintf for details. […]

Hello,

Thanks a lot for providing this beautiful program. But I am facing some problem with it. On my matlab (Version 7.4.0.287 (R2007a)), I am observing a strange thing. For instance, when I execute following command

>> cprintf([1,0.5,0],’and multi-\nline orange\n’);
and multi-
line orange

It works … But when I execute the next command, it gives error:

>> cprintf([0,1.0,0],’This is in green’);
Element #1:
??? Attempt to reference field of non-structure array.

Error in ==> cprintf>dumpElement at 335
if ~isjava(docElement), docElement = docElement.java; end

Error in ==> cprintf at 96
if ishandle(style), dumpElement(style); return; end

Again I get error :

>> cprintf([0.5,1.0,0],’This is in green’);
This is in green>> cprintf([0,0,1],’This is in green’);
Element #1:
??? Attempt to reference field of non-structure array.

Error in ==> cprintf>dumpElement at 335
if ~isjava(docElement), docElement = docElement.java; end

Error in ==> cprintf at 96
if ishandle(style), dumpElement(style); return; end

BUt this one works !!

>> cprintf(-[0,0,1],’This is in green’);
This is in green>> help printf

Can you please look into this anomaly and tell me if I am making any mistake.

Regards,
Swagat

Swagat – you are correct, this is indeed a bug: an edge-case caused by the fact that all the values you’ve entered for the style color (0.0 and 1.0) were also valid handles… I have fixed this and a few other issues – the updated CPRINTF is now online in the File Exchange (use the link contained in the article above).

how do u used the cprintf command?? each time i type it it says that undefined command cprintf….. i have downloaded the m file but how do i used it…im a bit of a newbies so please help…:)

@Taufiq – MathWorks stores CPRINTF in a zip file. After downloading this file, unzip it to any folder on your Matlab path (type “path” at the Matlab Command Prompt to see the path). The zip file contains cprintf.m which should now be available for use. Type “help cprintf” to see usage explanations and examples.

thanks a lot! its extrememly useful!

Thanks a lot! This tool is what I was looking for. Did you already figure out how to delete the extra space at the beginnen of each string?

@Matthias – I’m afraid not… Care to try?

I would like to make my comments in italics. How to do it using your discovery which is a little above my heads.

Thanks

@Kathy – as far as I know italics are not supported

I am waiting with baited breath for an update that allows one to change the FontName within the CW. There is nothing on the net on how to do it without using plots…

Good work!

@Giovanni – unfortunately, at the moment I do not know of any way to modify the CW fonts…

Really helpful for the community why MathWoks didn’t think about that before???!
Many thanks!

This function is really amazing! I cannot understand how MathWorks did not do this already. Thanks for making it.

However, it seems that R2011b (just released) has broken cprintf. I hope it can be fixed soon.

For all the people who have noted about cprintf’s issues with R2011b, the new version that was just uploaded fixes those problems, as well as the issue of the space (on R2011b only)

To whom it may concern: here is another useful hack (not really undocumented but one of the most underrated/unknown), that I have been using to replace the last few characters at the end of progressbar-like message strings inside loops.

step 1:

>> fprintf('progress: ..... 50%%\n'); 
progress: ..... 50%

step 2:

>> fprintf('progress: ..... 50%%\n'); fprintf(['\b\b\b\b\b. 60%%\n']);
progress: ...... 60%

similarly, step 3 (blinking text):

>> fprintf(['off\n']); for n=1:10, pause(0.5); fprintf(['\b\b\b\bon \n']); pause(0.5); fprintf(['\b\b\b\boff\n']); end
on   (toggles on/off each second)

step 4 (in a loop):

>> fprintf('progress:  00%%\n'); for n=1:10, pause(1); fprintf(['\b\b\b\b\b. %d%%\n'],10*n); end
progress: .....well, this text will change once a second

The pause command in the example represents a sequence of time-consuming operations. Note that we don’t need any timer objects, GUI callbacks, class events, Java, com.mathworks.etc here. Just raw C format specifications, doing their dirty deeds since Matlab 5 (or earlier). The general strategy should also work with cprintf, so thanks Yair we can finally see those progressbars grow in any color.

@Helge – you could try to use ‘\r’ instead of multiple ‘\b’

@Yair, \r is nice to clear an entire line back to its beginning, but the content is nevertheless displayed on a new line, as with \n. I tried the following to check this (with as well as without extra \b on either side of \r):

>> fprintf(['off\n']); for n=1:10, pause(0.5); fprintf(['\b\ron \n']); pause(0.5); fprintf(['\b\roff\n']); end
on
off
on
off
...

The multiple \b solution (+repmat, if this makes things simpler), in contrast, overwrites the last line with either on or off, so that the progress message is updated in-place, rather than adding a new line of output to the CW. In other words: the \b hack avoids that previous messages scroll out on top of the CW. Nevertheless, thx for \r, I was not yet aware of that.

I downloaded the latest cprintf() from file exchange for my R2011b, but it seems like the colors glitches (changes to unwanted color in between) when it’s displayed too fast. Here’s an example where I used cprintf(‘blue’, …)

^[11]

All the text in tht screencap is supposed to be in blue but some characters turned red and black in between.

Thanks for writing such a great program and I’d really appreciate any time looking into the issue.

@Hoi – it’s probably an ^[12]. Try adding a small pause(0.1) after each line is displayed, and/or use less colors i.e. regular black for all the regular text, using fprintf rather than cprintf.

Hi Yair,

Congratulations for your code!

I need a suggestion.. I want to print some strings (with variables) in a file, how I can colorize it with your code?

Now, my black and sad words are printed in the follows:

fprintf(id_handler, ‘Tipus de sensor: %s \n’, sensor); % geofon, electret i piezo
fprintf(id_handler, ‘Pes de la pedra: %s \n’, weigth); % 3.5kg, 9.5kg, 12kg…
fprintf(id_handler, ‘Distància de la caiguda: %s \n’, dist); %1m, 3m, 6m…
fprintf(id_handler, ‘Lloc: %s \n’, place); % cova, balma,
fprintf(id_handler, ‘Tipus de terra: %s \n’, soil); %argila, roca
fprintf(id_handler, ‘Guany: %s \n’, gain); % màxim, mínim, mig

How I write this words with colors and different styles?

Thank you very much!

@Roser – File text is colored by the editor application, different editors display colors differently. Text files do not typically have colors in editors

Dear Yair,
First of all, congratulations for you excellent site. I’d like to show some words in bold in the command window. For example, in Matlab 2012a, when you type >>help mean, the word “mean” in the displayed help is in bold. So it must be possible to print words in bold in the command window, but I cannot figure how. For example, disp(”<b> hello </b>”) does not work. Thank you very much for your time.

@Peter – Matlab indeed added a fourth custom attribute (to the list of three attributes listed in the article above): BoldStartTokens. Unfortunately, this appears to be an immutable array of numeric position indices, that I have so far not found a way to modify. Removing/adding the attribute also fails (a javax.swing.text.StateInvariantError: Illegal cast to MutableAttributeSet Java exception is thrown). I’ll update cprintf if and when I ever find a workaround…

@Peter – it turns out the answer is much simpler than messing around with the internal attributes – simply use <strong> rather than <b>:

fprintf('not bold,  bold \n')

that’s awesome !

Thank you very much Yair!!! For everyone’s info, fprintf(‘not bold, <strong> bold </strong>\n’) works on R2012a, R2011b, (cannot test in R2011a,sorry), but not in R2010b … or previous.

@Peter – FYI, this feature was added in R2011b. My article next week will expand on this issue.

Hi Yair.

I have been using cprintf with Matlab R2011b (win7, x64) for a little while now and have noticed a few glitches:
– Printing one character with cprintf messes up the previous print. Basically cprintf recolors the previous print + the new one (1character) with the new color. (and sometime it’s even more random, but this one is consistent).
-printing some strings make some color appear when it shouldn’t. I have a script where it is very reproduce-able (>90% of the time), but still there is a randomness part that I cannot manage to eliminate.

Did you notice these problems too ?
PS: I would like to work on these problems myself but Matlab’s debugger is always spitting text in the Command Window, making it really hard to troubleshoot the cprintf/fprintf functions. How do you work around that ?

@Raphael – indeed so. This happens because Matlab has internal logic to “optimize” the formatting by merging adjacent elements. This is the reason that I’ve used the extra space separator between cprintf elements in R2011a and earlier releases (see lines #153-161).

Debugging is indeed very difficult. For this reason I’ve used the dumpElement function (lines #381-427). I also used the trick of looking at a previously-displayed docElement – this way whatever extra text is displayed in the Command Window will not affect the docElement so we can safely “play around” with it. I’m not saying it’s easy. It’s pretty difficult even for me…

oh yeah, huh that’s a rather useful trick.
Do you know if it would be possible to tunnel the output in a separate window / file ?
That way we could separate the matlab outputs and the ones from our code.

PS: I’ve finally narrowed down the erratic red displays. It comes up when I use cprintf with % signs to display. One seem ok, but when playing around with several ones, the output color changes between black and red.

@Raphael – I see no reason why you couldn’t funnel the output into a separate window / file. At some point during the creation/debugging of cprintf I even contemplated this myself, but in the end it was not necessary. But you might find it useful in your case.

[…] A reader comment last week sent me on a short wild goose chase, that had an interesting and useful conclusion. […]

[…] my cprintf utility, which was selected as POTW, was quickly deselected as POTW because of this very issue […]

Hello Yair,

Thanks very much for your very interesting and extremely useful posts. I have a question regarding one of your suggestions to output the MATLAB command window on a GUI text box (see below; I found this on MATLAB Answers at ^[13] ). This is really nice and to some extent solved my problem. However, this does not work when I run my application in the deployed mode (i.e. when the executable version of my app runs using the MCR). Is there any solution to make this work in the deployed mode? Thanks very much for your help.

Regards,
Amir

– – – – – – – – – – – – – – –
You can access the CW text programmatically as follows:

jDesktop = com.mathworks.mde.desk.MLDesktop.getInstance;
jCmdWin = jDesktop.getClient('Command Window');
jTextArea = jCmdWin.getComponent(0).getViewport.getView;
cwText = char(jTextArea.getText);

You can place a callback that will update your GUI whenever new text is added to the CW:

set(jTextArea,'CaretUpdateCallback',@myUpdateFcn)

@Amir – I do not know of a way to automatically trap console output in deployed mode. The best solution is to use a custom output function that does what you need, rather than using standard disp or fprintf.

Wow !Wow!
thank you very Much, this is exactly what I’m trying to make in MATLAB this morning, a great help from you
thank you very much !

Hi Yair,

I have read your posting and answer for the command window output catching.
I tried to use your method to send the command window outputs to the my own GUI.

However, it doesn’t show the CW outputs in the status box of my GUI. Could you check the part of script?

function status_Callback(hObject, eventdata, handles)
% hObject    handle to status (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of status as text
%        str2double(get(hObject,'String')) returns contents of status as a double

jDesktop=com.mathworks.mde.desk.MLDesktop.getInstance;
jCmdWin=jDesktop.getClient('Command Window');
jTextArea=jCmdWin.getComponent(0).getViewport.getView;

cwText=char(jTextArea.getText);
hh=set(jTextArea,'CaretUpdateCallback',@runbatch_Callback);
str=get(hh,'String');
hset(handles.status,'String',str);

Thanks in advance,
CH.

@CH – What exactly are you trying to set hh to?! what’s wrong with setting your status box directly to cwText?

If I use the following line

set(handles.status,'String',cwText); 

in the status box of my GUI, it does not show the updated outputs dynamically.
I could see only first several lines which depends on the status box size.

You need to set the callbacks to update the text dynamically, of course.
If you’d like me to help you debug your specific issue, contact me by email for a short consulting.

Dear Yair,
Great effort, From some of the previous discussion can I conclude that I can’t use cprintf to print text to a file in color?
Is there an alternative way to print colorful text to files?. I don’t need text to be displayed in command window I need it in a file.

@Ahmed – you can use COM to place the text/data in an Excel/Word/PowerPoint file and then color the relevant parts just as you would do manually. Basically you need to invoke a series of COM (=VBA) commands from Matlab, but for the specific details you will need to search elsewhere. This is way beyond the scope of a post comment.

Thanks very much, you guided me to the way and I will check it.

Would italicized text be possible?

no Alex

Hello Yair,
is it possible to set the text background color as well (not for the whole command window)?

Not as far as I know…