Newbie: Pdf doesnt print correctly

[rajil.s]

Hi,

I am starting out with qwt and my intentions are to create a pdf of a pot without displaying any graphics. Unfortunately, the following code produces a pdf (see file.pdf) without axis and points. Please could somebody point out where i am going wrong

QwtPlot *plot=new (QwtPlot);
 
                   plot->setTitle( "Result" );
                     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("Curve");
                         curve->setPen( QPen( Qt::blue, 4 ) ),
                         curve->setRenderHint( QwtPlotItem::RenderAntialiased, false );
 
                         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);
 
                      QwtPlotRenderer renderer;
                      renderer.setDiscardFlag(QwtPlotRenderer::DiscardBackground, false);
                      renderer.setLayoutFlag(QwtPlotRenderer::KeepFrames, true);
                      renderer.renderDocument(plot, "file.pdf", QSizeF(300, 200), 85);

QwtPlot *plot=new (QwtPlot);

                   plot->setTitle( "Result" );
                     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("Curve");
                         curve->setPen( QPen( Qt::blue, 4 ) ),
                         curve->setRenderHint( QwtPlotItem::RenderAntialiased, false );

                         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);

                      QwtPlotRenderer renderer;
                      renderer.setDiscardFlag(QwtPlotRenderer::DiscardBackground, false);
                      renderer.setLayoutFlag(QwtPlotRenderer::KeepFrames, true);
                      renderer.renderDocument(plot, "file.pdf", QSizeF(300, 200), 85);

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[Uwe]

You have to do a replot before rendering your pdf.

Uwe