qwt or GNUplot or others...?

[didierB]

Hello all,
I write because I like to know which library you use to plot your graphs usually in your programs. I do programs that calculations the evolution of different magnitude in time and I would like for each time step plot the results.
Basically to have a dynamic graph.

Previously I was using qwt but I'm no expert in this library and I saw a lot of disadvantages and I wonder if with other libraries is simpler.
(it might be just me who can not use it properly)

Here is the program I have (schematically):

while (i <iFinal)
{
calcul.run ();
graphique.plot ();
i    ;
}

at each time step "i" I want to do a calculation and Live Display on my curve (without losing the points I have already drawn on the curve).


With qwt:
=> I had a lot of trouble with this library. First, to plot points without deleting the other i have for each time step "i" to plot all the results. Because, by default it updating the graph and delete everything else and keeps only the last point .
=> My second problem is also in the ease of use. perhaps we can use qwt QtDesigner but with me it don't works and i have to programm all the management of windows and qwt graphics... is difficult for a non informaticien like me

  GNU plot
I really do not know how it works and I like to have your opinion on this. D'after that I realized that reads text files and it draw a curve from two vectors (X and Y).

Can be plot in a real time ?

=> Thank you in advance for any information


ps : in reality, i want to plot a graphique "subplot" in matlab (see google image : subplot. By qwt i can but is very difficult without Qtdesigner