QT 4.5 and Plotting data

[Lezer]

Hello,

I am newbie using QT, I need to made some plots and histogram. Searching in the web I see QWT and QCustomPlot. I would not use QWT because you need to add a new library into device, and QCustomPlot it isn't for QT 4.5.

is there another libraty like QCustomPlot?

Thank you

[Uwe]

You are asking for a library, but don't want to use Qwt because it is a library ?

Uwe

[Lezer]

More or less yes. I want something like QCustomPlot, but QT 4.5 compatible code.

[Uwe]

You can always copy the code of an open source library into your source tree ( taking care of the license !) instead of using it as library - there is nothing special about QCustomPlot beside that it propagates this way. So this is no criteria for a package ( the other way it is: when you need a library and there is none ).

I'm afraid you won't find something else than Qwt for Qt 4.5, but you can easily strip it down to a smaller size ( and copy the files to your project even if IMHO this doesn't makes much sense ). In qwt/src/src.pro you can see the list of files that are needed for the plot classes only - when building the library you can configure to build them only in qwtconfig.pri ). Additionally you can remove more files for the plot items you don't need ( f.e for curves only ).

As author of the Qwt package I don't want to compare packages, but I don't agree that things are much easier than this code:

#include <qapplication.h>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_grid.h>
#include <qwt_symbol.h>
#include <qwt_legend.h>
 
int main( int argc, char **argv )
{
    QApplication a( argc, argv );
 
    QwtPlot plot;
    plot.setTitle( "Plot Demo" );
    plot.setCanvasBackground( Qt::white );
    plot.setAxisScale( QwtPlot::yLeft, 0.0, 10.0 );
    plot.insertLegend( new QwtLegend() );
 
    QwtPlotGrid *grid = new QwtPlotGrid();
    grid->attach( &plot );
 
    QwtPlotCurve *curve = new QwtPlotCurve();
    curve->setTitle( "Some Points" );
    curve->setPen( QPen( Qt::blue, 4 ) ),
    curve->setRenderHint( QwtPlotItem::RenderAntialiased, true );
 
    QwtSymbol *symbol = new QwtSymbol( QwtSymbol::Ellipse,
        QBrush( Qt::yellow ), QPen( Qt::red, 2 ), QSize( 8, 8 ) );
    curve->setSymbol( symbol );
 
    QPolygonF points;
    points << QPointF( 0.0, 4.4 ) << QPointF( 1.0, 3.0 )
        << QPointF( 2.0, 4.5 ) << QPointF( 3.0, 6.8 )
        << QPointF( 4.0, 7.9 ) << QPointF( 5.0, 7.1 );
    curve->setSamples( points );
 
    curve->attach( &plot );
 
    plot.resize( 600, 400 );
    plot.show();
 
    return a.exec();
}

#include <qapplication.h>
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_grid.h>
#include <qwt_symbol.h>
#include <qwt_legend.h>

int main( int argc, char **argv )
{
    QApplication a( argc, argv );

    QwtPlot plot;
    plot.setTitle( "Plot Demo" );
    plot.setCanvasBackground( Qt::white );
    plot.setAxisScale( QwtPlot::yLeft, 0.0, 10.0 );
    plot.insertLegend( new QwtLegend() );

    QwtPlotGrid *grid = new QwtPlotGrid();
    grid->attach( &plot );

    QwtPlotCurve *curve = new QwtPlotCurve();
    curve->setTitle( "Some Points" );
    curve->setPen( QPen( Qt::blue, 4 ) ),
    curve->setRenderHint( QwtPlotItem::RenderAntialiased, true );

    QwtSymbol *symbol = new QwtSymbol( QwtSymbol::Ellipse,
        QBrush( Qt::yellow ), QPen( Qt::red, 2 ), QSize( 8, 8 ) );
    curve->setSymbol( symbol );

    QPolygonF points;
    points << QPointF( 0.0, 4.4 ) << QPointF( 1.0, 3.0 )
        << QPointF( 2.0, 4.5 ) << QPointF( 3.0, 6.8 )
        << QPointF( 4.0, 7.9 ) << QPointF( 5.0, 7.1 );
    curve->setSamples( points );

    curve->attach( &plot );

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

    return a.exec();
}

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Uwe