How i can plot result in my GUI ?

[21did21]

Hello world,

i have raed a tutorial which it speak about curve with QWT. In this tutorial i find this example to plot a curve during compilation:


this is the code:

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
 
int main(int argc, char** argv)
{
    QApplication app(argc,argv);
    QwtPlot myPlot;
    QwtPlotCurve myCurve;
 
    myCurve.attach(&myPlot);
 
    QVector<double> x(5);
    QVector<double> y(5);
 
    for(int i=0;i<5;i++)
    {
        x.append((double)i);
        y.append((double)(5-i));
    }
    myCurve.setData(x.data(),y.data(),x.size());
 
    myPlot.replot();
    myPlot.show();
    return app.exec();
}

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>

int main(int argc, char** argv)
{
    QApplication app(argc,argv);
    QwtPlot myPlot;
    QwtPlotCurve myCurve;

    myCurve.attach(&myPlot);

    QVector<double> x(5);
    QVector<double> y(5);

    for(int i=0;i<5;i++)
    {
        x.append((double)i);
        y.append((double)(5-i));
    }
    myCurve.setData(x.data(),y.data(),x.size());

    myPlot.replot();
    myPlot.show();
    return app.exec();
}

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this is the error:

==> see attached file

i don't why arguments are not good...

how i can plot this curve please?

thank you for your help

(the help of QWT is very difficult for my, i am a real beginner, it is the reason why i ask this)

[FelixB]

i have raed a tutorial which it speak about curve with QWT. In this tutorial i find this example to plot a curve during compilation:

this is a normal plot. nothing happens "during compilation".

the code is written for an older version of qwt. you have to adapt it to the current version. maybe there are more/other errors...

I suggest to take a look into the examples delivered with qwt. there are also quite simple plots.

Felix

[21did21]

thank you for your answer

this is a normal plot. nothing happens "during compilation".

ok

the code is written for an older version of qwt. you have to adapt it to the current version.

ok, but i don't know how i can adapt this... and i have read the exemple which are in Qwt6-0-0 but i don't understand anything, there is a lot of thing in each example, so i don't find the thing which are interesting for me...

can you help me lease

[Uwe]

What about this code: http://qwt.svn.sourceforge.net/viewv...22&view=markup

Uwe

[21did21]

thank you a lot, i like this example !!!
i understand a little now

---

Added after 1 33 minutes:

i have try to plote something but it don't work (i don't show something)

This is my main.cpp

#include <qapplication.h>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <vector>
#include "fonction.h"
 
using namespace std;
 
        int main(int argc, char **argv)
        {
            QApplication a(argc, argv);
            QwtPlot plot;
            QwtPlotCurve *curve = new QwtPlotCurve();
 
            for (int i=1;i<10;i++)
            {
            QPolygonF points;
            vector<double>coord;
            coord=fonction();
 
            points << QPointF( coord[0],coord[1] ) ;
 
            curve->attach( &plot );
            plot.replot();
            }
 
            plot.resize(600,400);
            plot.show();
 
            return a.exec();
        }

#include <qapplication.h>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <vector>
#include "fonction.h"

using namespace std;

        int main(int argc, char **argv)
        {
            QApplication a(argc, argv);
            QwtPlot plot;
            QwtPlotCurve *curve = new QwtPlotCurve();

            for (int i=1;i<10;i++)
            {
            QPolygonF points;
            vector<double>coord;
            coord=fonction();

            points << QPointF( coord[0],coord[1] ) ;

            curve->attach( &plot );
            plot.replot();
            }

            plot.resize(600,400);
            plot.show();

            return a.exec();
        }

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and my fonction:

#include <vector>
#include <ctime> // to generate random point
#include <cstdlib> // to generate random point
#include "fonction.h"
 
using namespace std;
 
vector<double>  fonction()
{
    vector<double> points;
    srand(time(0));
    points.clear();
 
    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 "fonction.h"

using namespace std;

vector<double>  fonction()
{
    vector<double> points;
    srand(time(0));
    points.clear();

    points.push_back(rand() % 1800);
    points.push_back(rand() % 500);

    return points;
}

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and his header:

#ifndef FONCTION_H
#define FONCTION_H
 
std::vector<double>  fonction();
 
#endif // FONCTION_H

#ifndef FONCTION_H
#define FONCTION_H

std::vector<double>  fonction();

#endif // FONCTION_H

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can you explain me, how i can plot this curve. I want to différente version: with line between point and without line

[FelixB]

your plot does not show anything because it has no data. you have to points you want to plot in a QPolygonF. But what happens to this Polygon? have a look at the example uwe posted.

btw, you should have the "attach" and "replot"-calls in your loop. that does not amke sense, it's sufficient to call both once after the loop.

[21did21]

sorry but i don't understand very well because my english is bad...
i don't understand how i can plot my points which are in the function "fonction". With my function i import 2 points for each loop, and after this a want to plot then with the previous.
i think i forget a line "curve->setSamples( points ); " no ?

(now i can't test i am not at home)

[FelixB]

yes, you have to call "setsamples" - after the loop. during the loop, you have to fill the QPolygonF with points.

this is simple c++, so I won't give you code. You'll learn more by finding the solution by yourself to give you some hints: you need *one* QPolygonF, not 10. You want, that this QPOlygonF contains 10 QPoints. You want to plot these 10 points=one polygon...

[21did21]

yes, you have to call "setsamples" - after the loop. during the loop, you have to fill the QPolygonF with points.
this is simple c++, so I won't give you code. You'll learn more by finding the solution by yourself to give you some hints: you need *one* QPolygonF, not 10. You want, that this QPOlygonF contains 10 QPoints. You want to plot these 10 points=one polygon...

ok thank you for this explications, i test this evening...
see you

ps: juste one other think: is i don't want lines, just points what is the command which replace "Qpolygon" ?

[FelixB]

QPolygon is just an ordered collection of points - the data. how this data is painted is in the responsibility of QwtPlotCurve. Have a look at the API and search for something like "CurveStyle" - I don't know the exact method, the possible style types are n an enumeration.

[21did21]

ok, i will see this

[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

[21did21]

Hello world,

with your help i have done a GUI, but i add something to plut 6curves but i don't understand how i can send my results to the plot area....?

Can you see and try my programm please? how i can launch the plot? can you correct me?

it's difficult for me i am a beginner

main.cpp

#include <QApplication>
#include "MyMainWindow.h"
#include <QGridLayout>
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MyMainWindow fenetre;
    fenetre.show();
    return app.exec();
}

#include <QApplication>
#include "MyMainWindow.h"
#include <QGridLayout>
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MyMainWindow fenetre;
    fenetre.show();
    return app.exec();
}

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MyMainWindow.h

#ifndef MYMAINWINDOW_H
#define MYMAINWINDOW_H
 
#include <QApplication>
#include <QWidget>
#include <QPushButton>
#include <QMessageBox>
#include <qwt_plot_curve.h>
#include <qwt_plot.h>
 
class MyMainWindow : public QWidget
{
    Q_OBJECT
 
public:
    explicit MyMainWindow(QWidget* parent = 0);
    void myRunSlot();
    void plotValuesFromFunction()
 
private:
    QPushButton *BUTTONRun;
    QPushButton *BUTTONQuit;
    QPushButton *BUTTONAbout;
    QPushButton *BUTTONContact;
 
    QwtPlot *myPlot1;
    QwtPlot *myPlot2;
    QwtPlot *myPlot3;
    QwtPlot *myPlot4;
    QwtPlot *myPlot5;
    QwtPlot *myPlot6;
 
    QwtPlotCurve myCurve1;
    QwtPlotCurve myCurve2;
    QwtPlotCurve myCurve3;
    QwtPlotCurve myCurve4;
    QwtPlotCurve myCurve5;
    QwtPlotCurve myCurve6;
 
};
#endif // MYMAINWINDOW_H

#ifndef MYMAINWINDOW_H
#define MYMAINWINDOW_H

#include <QApplication>
#include <QWidget>
#include <QPushButton>
#include <QMessageBox>
#include <qwt_plot_curve.h>
#include <qwt_plot.h>

class MyMainWindow : public QWidget
{
    Q_OBJECT

public:
    explicit MyMainWindow(QWidget* parent = 0);
    void myRunSlot();
    void plotValuesFromFunction()

private:
    QPushButton *BUTTONRun;
    QPushButton *BUTTONQuit;
    QPushButton *BUTTONAbout;
    QPushButton *BUTTONContact;

    QwtPlot *myPlot1;
    QwtPlot *myPlot2;
    QwtPlot *myPlot3;
    QwtPlot *myPlot4;
    QwtPlot *myPlot5;
    QwtPlot *myPlot6;

    QwtPlotCurve myCurve1;
    QwtPlotCurve myCurve2;
    QwtPlotCurve myCurve3;
    QwtPlotCurve myCurve4;
    QwtPlotCurve myCurve5;
    QwtPlotCurve myCurve6;

};
#endif // MYMAINWINDOW_H

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MyMainWindow.cpp

#include "MyMainWindow.h"
#include <QGridLayout>
#include <QHBoxLayout>
#include <qwt_plot_curve.h>
#include "RunSimulation.h"
#include <vector>
MyMainWindow::MyMainWindow(QWidget* parent) : QWidget(parent)
{
    QGridLayout* mainLayout = new QGridLayout();
    setLayout(mainLayout);
 
    myPlot1 = new QwtPlot();
    myPlot2 = new QwtPlot();
    myPlot3 = new QwtPlot();
    myPlot4 = new QwtPlot();
    myPlot5 = new QwtPlot();
    myPlot6 = new QwtPlot();
 
    myPlot1->setMinimumSize(200, 100);
    myPlot2->setMinimumSize(200, 100);
    myPlot3->setMinimumSize(200, 100);
    myPlot4->setMinimumSize(200, 100);
    myPlot5->setMinimumSize(200, 100);
    myPlot6->setMinimumSize(200, 100);
 
    QWidget* buttonWidget = new QWidget();
    QGridLayout* buttonLayout = new QGridLayout();
 
    BUTTONRun = new QPushButton("RUN");
    BUTTONQuit = new QPushButton("STOP");
    BUTTONAbout = new QPushButton("About");
    BUTTONContact = new QPushButton("Contact");
 
    buttonLayout->addWidget(BUTTONRun    ,0,0);
    buttonLayout->addWidget(BUTTONQuit   ,0,1);
    buttonLayout->addWidget(BUTTONAbout  ,1,0);
    buttonLayout->addWidget(BUTTONContact,1,1);
 
    buttonWidget->setLayout(buttonLayout);
 
    mainLayout->addWidget(myPlot1      ,0,0,1,1);
    mainLayout->addWidget(myPlot2      ,0,1,1,1);
    mainLayout->addWidget(myPlot3      ,0,2,1,1);
    mainLayout->addWidget(myPlot4      ,1,0,1,1);
    mainLayout->addWidget(myPlot5      ,1,1,1,1);
    mainLayout->addWidget(myPlot6      ,1,2,1,1);
    mainLayout->addWidget(buttonWidget ,0,3,1,1);
 
    myCurve1.attach(&myPlot1);
    myCurve2.attach(&myPlot2);
    myCurve3.attach(&myPlot3);
    myCurve4.attach(&myPlot4);
    myCurve5.attach(&myPlot5);
    myCurve6.attach(&myPlot6);
 
    QObject::connect(BUTTONQuit, SIGNAL(clicked()), qApp, SLOT(quit()));
    QObject::connect(BUTTONAbout, SIGNAL(clicked()), qApp, SLOT(aboutQt()));
    QObject::connect(BUTTONRun, SIGNAL(clicked()), qApp, SLOT(myRunSlot()));
}
void MyMainWindow::myRunSlot()
{
    RunSimulation();
}
void MyMainWindow::plotValuesFromFunction()
{
    QVector<double> x(1);
    QVector<double> y(1);
    vector<double> points;
 
    x.append( points[0] );
    y.append( points[1] );
 
    myCurve1.setSamples(x.data(),y.data(),x.size());
    myCurve2.setSamples(x.data(),y.data(),x.size());
    myCurve3.setSamples(x.data(),y.data(),x.size());
    myCurve4.setSamples(x.data(),y.data(),x.size());
    myCurve5.setSamples(x.data(),y.data(),x.size());
    myCurve6.setSamples(x.data(),y.data(),x.size());
    myPlot.replot();
    myPlot.show();
}

#include "MyMainWindow.h"
#include <QGridLayout>
#include <QHBoxLayout>
#include <qwt_plot_curve.h>
#include "RunSimulation.h"
#include <vector>
MyMainWindow::MyMainWindow(QWidget* parent) : QWidget(parent)
{
    QGridLayout* mainLayout = new QGridLayout();
    setLayout(mainLayout);

    myPlot1 = new QwtPlot();
    myPlot2 = new QwtPlot();
    myPlot3 = new QwtPlot();
    myPlot4 = new QwtPlot();
    myPlot5 = new QwtPlot();
    myPlot6 = new QwtPlot();

    myPlot1->setMinimumSize(200, 100);
    myPlot2->setMinimumSize(200, 100);
    myPlot3->setMinimumSize(200, 100);
    myPlot4->setMinimumSize(200, 100);
    myPlot5->setMinimumSize(200, 100);
    myPlot6->setMinimumSize(200, 100);

    QWidget* buttonWidget = new QWidget();
    QGridLayout* buttonLayout = new QGridLayout();

    BUTTONRun = new QPushButton("RUN");
    BUTTONQuit = new QPushButton("STOP");
    BUTTONAbout = new QPushButton("About");
    BUTTONContact = new QPushButton("Contact");

    buttonLayout->addWidget(BUTTONRun    ,0,0);
    buttonLayout->addWidget(BUTTONQuit   ,0,1);
    buttonLayout->addWidget(BUTTONAbout  ,1,0);
    buttonLayout->addWidget(BUTTONContact,1,1);

    buttonWidget->setLayout(buttonLayout);

    mainLayout->addWidget(myPlot1      ,0,0,1,1);
    mainLayout->addWidget(myPlot2      ,0,1,1,1);
    mainLayout->addWidget(myPlot3      ,0,2,1,1);
    mainLayout->addWidget(myPlot4      ,1,0,1,1);
    mainLayout->addWidget(myPlot5      ,1,1,1,1);
    mainLayout->addWidget(myPlot6      ,1,2,1,1);
    mainLayout->addWidget(buttonWidget ,0,3,1,1);

    myCurve1.attach(&myPlot1);
    myCurve2.attach(&myPlot2);
    myCurve3.attach(&myPlot3);
    myCurve4.attach(&myPlot4);
    myCurve5.attach(&myPlot5);
    myCurve6.attach(&myPlot6);

    QObject::connect(BUTTONQuit, SIGNAL(clicked()), qApp, SLOT(quit()));
    QObject::connect(BUTTONAbout, SIGNAL(clicked()), qApp, SLOT(aboutQt()));
    QObject::connect(BUTTONRun, SIGNAL(clicked()), qApp, SLOT(myRunSlot()));
}
void MyMainWindow::myRunSlot()
{
    RunSimulation();
}
void MyMainWindow::plotValuesFromFunction()
{
    QVector<double> x(1);
    QVector<double> y(1);
    vector<double> points;

    x.append( points[0] );
    y.append( points[1] );

    myCurve1.setSamples(x.data(),y.data(),x.size());
    myCurve2.setSamples(x.data(),y.data(),x.size());
    myCurve3.setSamples(x.data(),y.data(),x.size());
    myCurve4.setSamples(x.data(),y.data(),x.size());
    myCurve5.setSamples(x.data(),y.data(),x.size());
    myCurve6.setSamples(x.data(),y.data(),x.size());
    myPlot.replot();
    myPlot.show();
}

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RunSimulation.h

#ifndef RUNSIMULATION_H
#define RUNSIMULATION_H
 
void RunSimulation();
 
#endif // RUNSIMULATION_H

#ifndef RUNSIMULATION_H
#define RUNSIMULATION_H

void RunSimulation();

#endif // RUNSIMULATION_H

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RunSimulation.cpp

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <vector>
#include "function.h"
#include "RunSimulation.h"
using namespace std;
void RunSimulation()
{
    vector<double> points;
    for (int i=1;i<10;i++)
    {
    points.clear();
    points=function();
    //!! for each "i" i want to send result to the 6plots... but i don't know how...?
    }
}

#include <QApplication>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <vector>
#include "function.h"
#include "RunSimulation.h"
using namespace std;
void RunSimulation()
{
    vector<double> points;
    for (int i=1;i<10;i++)
    {
    points.clear();
    points=function();
    //!! for each "i" i want to send result to the 6plots... but i don't know how...?
    }
}

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function.h

#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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function.cpp

#include <vector>
#include <ctime> // to generate random point
#include <cstdlib> // to generate random point
#include "function.h"
#include "windows.h"
using namespace std;
vector<double>  function()
{
    vector<double> points;
    srand(time(0));
    points.clear();
    Sleep(1);
    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.h"
#include "windows.h"
using namespace std;
vector<double>  function()
{
    vector<double> points;
    srand(time(0));
    points.clear();
    Sleep(1);
    points.push_back(rand() % 1800);
    points.push_back(rand() % 500);
    return points;
}

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it 's very important for me to plot this but it's very difficult, i am not an "informaticien"
i hope you can help me

[21did21]

this code can work, but it difficult for me to send data from the "function" to my plots

i hope that you can help me,

thank you

[stampede]

i don't understand how i can send my results to the plot area....?

Looks like the plot area belongs to mainWindow, so in order to send it some data, you'll need to expose main window object somehow.
Where the RunSimulation() method is called ? You want to call it, for example, on button click ?

[21did21]

thank you for your answer

Looks like the plot area belongs to mainWindow, so in order to send it some data, you'll need to expose main window object somehow.

sorry, i don't understand this: "you'll need to expose main window object somehow"

Where the RunSimulation() method is called ? You want to call it, for example, on button click ?

when i click on the button "Run" i tell the function "RunSimulation" and the code works

[stampede]

Simple solution is to make the RunSimulation() function return some data, so you can use it in MainWindow:

vector< vector<double> > RunSimulation()
{
    const int count = 9;
    vector< vector<double> > data;
    for (int i=0;i<count;i++)
    {
    data.push_back( function() );
    }
    return data;
}
 
// in main window:
void MyMainWindow::myRunSlot()
{
    vector< vector<double> > points = RunSimulation();
    // display the points in plot
}

vector< vector<double> > RunSimulation()
{
    const int count = 9;
    vector< vector<double> > data;
    for (int i=0;i<count;i++)
    {
    data.push_back( function() );
    }
    return data;
}

// in main window:
void MyMainWindow::myRunSlot()
{
    vector< vector<double> > points = RunSimulation();
    // display the points in plot
}

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In order to display the points, create a method that takes a vector<double> as an argument ( very simple modification of the plotValuesFromFunction() ) and call it for every vector in points vector.
Btw. use Qt container classes if you can.

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thank you for your help, but this is two remarks:

1°)
=> i can't change "RunSimulation" because in the reallity i don't work with this function, i work with a function "RunSimulation" that is huge and it's a void type.
=> in RunSimulation i don't calculate something, just i tell other method or function; it's like a "main.cpp"
so i propose this example because it's very close to me but without the all code, that is very long

2°)
for me it's interesting to see the evolution of my values during the calcul, so i don't want to see results at the end of calcul but step by step

i hope that this problem is not too difficult ?