Linux canvas
 

I have Ubuntu 14.04

There are many graphic packages but I may be forced to create my own because of the specific task I am dealing with. I am wondering if there is a way to generate a white canvas with the stipulation that I can use X-Y coordinates for input I need. Something very primitive.

Thanks, - A.

Qt should be fine for that, just create a window or app with a white background and then it all depends what you want to do for XY input; i.e. click or click-drag and so forth. But you can get the coordinates of mouse/finger actions and motions via the Qt even interface. Something much smaller is FLTK.

Perhaps this thread should be moved to Linux->Software to get more exposure.

rtmistler, thank you. Is Qt the same as Qt Creator? I just googled for it and found a few websites but nobody seems to explain in simple English what it actually does. Just as an example. Although it says that it is an editor. If I am on the right track, I will be able to try it only tomorrow.

Thanks, A.

QtCreator is part of Qt. Qt overall is a graphics ... framework, or it may be more correct to say it is a set of libraries which you can install.

I configure and build it from source to install it. I also do not use the QtCreator.

Most examples and answers to questions I've received when asking for or seeking help have been in the form of C++ code.

But you can start with the Creator and then choose your direction as you learn more about it.

Thank you again. I marked the thread as solved. A.

OK, it seems I installed Qt library but in the end realized it is commercial package. You have to download a bunch of stuff on top of that as a "FREE TRIAL" then pay $25 a month. Never in the world am I going to do this. I have no confidence it is what I ultimately need. Besides I may need it for a short period of time when my project runs, even if it works. It is unfair to point someone to a clearly commercial application without telling the truth.

rtmistler, you set me up. I suspect you are a part of this business. I unmarked the thread. Now it is UNSOLVED. Besides I have a bunch of trash in my directories. I will also report you.

AlexBB - Qt is a widely used software in the desktop linux world. The KDE desktop, the LXQt desktop, the vlc media player all use it on terms of the free software licensing option. They also provide a nonfree licensing option which costs money - the licensee gets the right to use Qt in nonfree software in return.

No need to accuse somebody of "setting" you up, or to report somebody. If you have a desktop linux installed, chances are that you also already got Qt installed (look for packages like "qtcore" and "qtgui"). For development work, you maybe need additional header files, a compiler (gcc plus Qt's own moc compiler) and an IDE (optional). QtCreator is such a IDE.

And the website of Qt is http://qt-project.org/. I don't know what this indian/british/hosted in ireland domain you found even is, but it's not the Qt rtmistler was talking about.

One smaller option for simple 2D graphics programming tasks could be Tk.

Qt can be used in an open source form. I also recommended FLTK in case you didn't notice. No I don't work for Qt.

Sorry, perhaps I overreacted. I just don't like downloading anything from the Internet. I am afraid to tell you the truth. Just very leery. I trust Ubuntu and prefer sudo apt-get command. Thanks, - A.

What programming language are you using? Of it is a script, Pyhton, TCL or Perl, Tk might be your friend. The learning curve takes about 20 minutes.

jlinkels

Gfortran, Fortan 90, etc(mostly) & C++. I am trying to make it with gnuplot now since I am more familiar with it. I began looking for alternatives when I realized that I could not get any gnuplots on Ubuntu 14.04 and 13.04 (?) versions, lost quite a bit of time. I think they have bugs gnuplot related. Now I reimaged my laptop with Ubuntu 12.04 and am getting beautiful pictures but I still have a way to go. My tasks are very specific. So my thrust into the unknown (Qt, and others) began before I realized what was going on with gnuplot. Now I seem to be on a right track.

Thank you, - A.

aptitude (sudo apt-get) downloads from the internet in order to install packages.

Very many people will tell you reasons why not to trust Ubuntu because it reports data back to their server about your system. You can opt out of that, but I do not believe it is the default behavior.

Sounds like you wanted to plot. Granted you did mention XY coordinates, but it wasn't clear if you just wanted to render information or provide a drawing canvas and use XY coordinates, given the title of the thread I guessed drawing canvas. Therefore I would not actually use Qt for that even though there's a graphing library it has, QwtPlot or something, I tried using it once and it was difficult.

gnuplot is very good, in fact I believe the defacto choice for plotting, it's been around for about 20 years.

I did a quick search and here's a wiki showing a number of graphing packages, but you need to check that they are for Linux, GPl, open source, and also free, a good deal of them are. And never used it, but I've heard good reviews of MayaVi.

http://en.wikipedia.org/wiki/List_of_graphing_software

I've used gnuplot which I think is part of the plotutils package.

OMG, never knew that many programs exist. I guessed not even 10% of that. I am missing PGFPlot in that overview. Granted PGFPlot is specialized, but the scope of that table is quite broad anyway.
The package name is simply gnuplot.

jlinkels