Qt 3.x + Qwt - Advice on programming and plotting.

Hello everyone,

I am looking for some guidance and advice from you people here, I got a peculiar situation where I would like your help. Just hear out my situation first with patience. Your contribution/reply will be deeply appreciated.

I got a little self induced project work. Where I am to work in Real time linux (RT Linux - FIFO operation) - So I am using Red Hat 9 Shrike, have to use only Qt 3.1 (Yikes! I know - basically should work in Kernal 2.4) and should use Qwt in order to draw out graphs for scientific visualization - basically real-time plotting. And also please note that I cannot change on the tools I have to use here. Kind of obligatory.

Now my questions are :

1. For real-time plotting / visualization - Is there no other library or extension for Qt other than Qwt?

2. Which version of Qwt is most compatible and easy to work it ? Because Qwt 0.4.1 (4.1) and also I think Qwt 5.x support Qt3.x and above, Although I think I read that documentations of Qwt with Qt4.x + are only available. So can I use the Qwt 5.x for my project here, will it hinder or clash with support of Qt 3-1?

3. What's with the version of Qwt? Is Qwt(0.4.1) = Qwt 4.1 ? If so why? and Qwt 5.x or is it Qwt 0.5.1?? Little confused here.

4. I am using Qt Designer 3.1, is there a Qwt plugin for Qt Designer( Mind you - not Creator - Creator is not even available for Qt 3.1), If so then please help me on getting it on to my Designer. Was not able to do it today when I was fiddling around with Qwt 0.4.1.

5.Whats the BEST resources or tutorial for Qwt? I know Qwt has its own documentation, but its not lucid at all. Any one know other resources, although I squandered the Internet but couldn't come up with much.

6. I suppose Qt support OpenGL, Can it be used for real-time plotting ? Please accept my incompetence on understanding of OpenGL. All I know is that its used for rendering graphics, but I ask is, can it be used for plotting?

7.On running the examples of Qwt. I did install Qwt according to the ReadMe file included in it. But I am unable to run and compile the examples with...

Code:

---

# qmake -project
# qmake -o makefile testfile.pro
# make clean
# make

---

Let me mention here - I did set TMAKE and LD_LIBRARY_PATH (whatever theie name were) to the /usr/qt3.1/lib folder.
And the problem that I am facing is when I try to make the .pro file using the qmake command its actually doesnt write the proper file as opposed to one already written when compiling and installing Qwt. So as a work around I used the .pro already generated and managed to compilethe examples. ( I will try and post the exact code in the .pro tomorrow, so maybe you will be able to help me better.)

That's all for now. I am really sorry to bandger my post with so many question, but as you can see that I had a very peculiar situation. And very little information is available over the Internet for Qt3.x, so I turning to your veterans here, Hope to get some replys.

Anyway if you feel that I should I opened different topic for each or maybe have posted this is wrong section. Please accept my humble apology.

With regards.

No one here to help? I know its Qt 3.x, not many people will have any idea about it. But I was hoping maybe some veteran here could help me out. Hope something turns up this weekend.

Qwt up to version 6.0.0 (but not including) supports Qt3.
As far as I know online documentation for Qwt is up to date although each source code has documentation current for that version.

Anything can be used for ploting, OpenGL, QGraphicsSceen (but I think you don't have that in Qt3), or simple QWidget (in essence Qwt is QPolygon drawn on QWidget + plenty of convinience functions).
All depends on what kind of performance you're looking for.

Take a look at examples to learn Qwt, unfortunatley documentation is very vague.

Quote:

---

Originally Posted by Spitfire

Qwt up to version 6.0.0 (but not including) supports Qt3.
As far as I know online documentation for Qwt is up to date although each source code has documentation current for that version.

Anything can be used for ploting, OpenGL, QGraphicsSceen (but I think you don't have that in Qt3), or simple QWidget (in essence Qwt is QPolygon drawn on QWidget + plenty of convinience functions).
All depends on what kind of performance you're looking for.

Take a look at examples to learn Qwt, unfortunatley documentation is very vague.

---

Thanks you VERY VERY VERY much for replying. I dont know how I missed it, didnt see it the last 2 days. Even though I was checking everyday, every single time I logged on.

Anyway coming back, just to assure myself Qwt upto 6.0.0 will work fine in qt3 right? I have to make it work on Real Time Linux - any idea about it?

And is there a Qwt plugin for Qt Designer 3.1? Though I am gonna experiment now, installing various version - but little heads up or tip would be good.

Sorry, I've no idea about RTL ;/
And yes, support for Qt3 was dropped in Qwt 6.x.x so anything before that should work just fine.

I know there's a plugin for the designer, but most time I've heard about it was mentioned in context of QtCreator on windows.
I would imagine you can use it with QtDesigner alone but you'll have to try it yourself - I personally don't use it :)

Here's few links that may help you, they are all for windows but you may get an idea what needs to be done:
http://doc.qt.nokia.com/qtcreator-2....g-plugins.html
http://qwt.sourceforge.net/qwtinstall.html
http://stackoverflow.com/questions/1...gin-for-qt-4-5
http://www.qtforum.org/article/20071...al-studio.html

Quote:

---

Originally Posted by amitahire

Anyway coming back, just to assure myself Qwt upto 6.0.0 will work fine in qt3 right?

---

Qwt 5.2 works for Qt 3.3 - Qt 3.1 is way older.

I can't remember which version of Qwt works with Qt 3.1 - I'm afraid you will have to go back in history of the Qwt releases to find the most recent version, that works for Qt 3.1.

Uwe