How i can plot result in my GUI ?

[21did21]

I'm too bad I did not understand "Qpolygon" so I tried something else:

main.cpp

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <vector>
#include "function.hpp"
using namespace std;
int main(int argc, char** argv)
{
    QApplication app(argc,argv);
    QwtPlot myPlot;
    QwtPlotCurve myCurve;
    myCurve.attach(&myPlot);
    for (int i=1;i<10;i++)
    {
    vector<double> points;
    points=function();
    QVector<double> x(1);
    QVector<double> y(1);
    x.append( points[0]);
    y.append( points[1]);
    }
    myCurve.setSamples(x.data(),y.data(),x.size());
    myPlot.replot();
    myPlot.show();
    return app.exec();
}

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <vector>
#include "function.hpp"
using namespace std;
int main(int argc, char** argv)
{
    QApplication app(argc,argv);
    QwtPlot myPlot;
    QwtPlotCurve myCurve;
    myCurve.attach(&myPlot);
    for (int i=1;i<10;i++)
    {
    vector<double> points;
    points=function();
    QVector<double> x(1);
    QVector<double> y(1);
    x.append( points[0]);
    y.append( points[1]);
    }
    myCurve.setSamples(x.data(),y.data(),x.size());
    myPlot.replot();
    myPlot.show();
    return app.exec();
}

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function.cpp

#include <vector>
#include <ctime> // to generate random point
#include <cstdlib> // to generate random point
#include "function.hpp"
using namespace std;
vector<double>  function()
{
    vector<double> points;
    srand(time(0));
    points.clear();
    Sleep(5000);
    points.push_back(rand() % 1800);
    points.push_back(rand() % 500);
    return points;
}

#include <vector>
#include <ctime> // to generate random point
#include <cstdlib> // to generate random point
#include "function.hpp"
using namespace std;
vector<double>  function()
{
    vector<double> points;
    srand(time(0));
    points.clear();
    Sleep(5000);
    points.push_back(rand() % 1800);
    points.push_back(rand() % 500);
    return points;
}

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function.hpp

#ifndef FUNCTION_HPP
#define FUNCTION_HPP
std::vector<double>  function();
#endif // FUNCTION_HPP

#ifndef FUNCTION_HPP
#define FUNCTION_HPP
std::vector<double>  function();
#endif // FUNCTION_HPP

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but this code say:

X and Y are not declared in this scope, but i have declared this values???

can you help me
i bloc with Qwt until 3week just to plot a plot with some points

[FelixB]

you need some more c++-knowledge, your problems are not qwt-related. the vectors x and y are declared within scope of the loop. you can't access them when you left the loop. have you ever filled an array with a loop?

in "fonction", you don't need the call "points.clear()" since the vector is empty when you create it. is there any reason for the "sleep(5000)"?

ok, I'll help you with some code. I suggest to get back to QPolygonF. Then you can return a QPointF in "fonction()" directly. This is more intuitive and you can forget all the QVector stuff you don't need... I'll give you the modified loop and let you adapt "fonction()" by yourself. I'll help you when you can't manage that.

QPolygonF polygon;
for(unsigned int i=0; i<10; i++)
  polygon << fonction();
 
curve->setSamples(polygon);  // maybe you need more parameters...

QPolygonF polygon;
for(unsigned int i=0; i<10; i++)
  polygon << fonction();

curve->setSamples(polygon);  // maybe you need more parameters...

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[21did21]

is there any reason for the "sleep(5000)"?

because my real code take a lot of time to calcul my values and here i want to simul this waiting time