qt组直方图例子-qwt

qwt中 多组直方图的例子如下：

main.cpp代码

1. #include  
2. #include  
3. #include  
4. #include  
5. #include  
6. #include "barchart.h" 
7.  
8. class MainWindow: public QMainWindow 
9. { 
10. public: 
11.     MainWindow( QWidget * = NULL ); 
12.  
13. private: 
14.     BarChart *d_chart; 
15. }; 
16.  
17. MainWindow::MainWindow( QWidget *parent ): 
18.     QMainWindow( parent ) 
19. { 
20.     d_chart = new BarChart( this ); 
21.     setCentralWidget( d_chart ); 
22.  
23.     QToolBar *toolBar = new QToolBar( this ); 
24.  
25.     QComboBox *typeBox = new QComboBox( toolBar ); 
26.     typeBox->addItem( "Grouped" ); 
27.     typeBox->addItem( "Stacked" ); 
28.     typeBox->setSizePolicy( QSizePolicy::Fixed, QSizePolicy::Fixed ); 
29.  
30.     QComboBox *orientationBox = new QComboBox( toolBar ); 
31.     orientationBox->addItem( "Vertical" ); 
32.     orientationBox->addItem( "Horizontal" ); 
33.     orientationBox->setSizePolicy( QSizePolicy::Fixed, QSizePolicy::Fixed ); 
34.  
35.     QToolButton *btnExport = new QToolButton( toolBar ); 
36.     btnExport->setText( "Export" ); 
37.     btnExport->setToolButtonStyle( Qt::ToolButtonTextUnderIcon ); 
38.     connect( btnExport, SIGNAL( clicked() ), d_chart, SLOT( exportChart() ) ); 
39.  
40.     toolBar->addWidget( typeBox ); 
41.     toolBar->addWidget( orientationBox ); 
42.     toolBar->addWidget( btnExport ); 
43.     addToolBar( toolBar ); 
44.  
45.     d_chart->setMode( typeBox->currentIndex() ); 
46.     connect( typeBox, SIGNAL( currentIndexChanged( int ) ), 
47.              d_chart, SLOT( setMode( int ) ) ); 
48.  
49.     d_chart->setOrientation( orientationBox->currentIndex() ); 
50.     connect( orientationBox, SIGNAL( currentIndexChanged( int ) ), 
51.              d_chart, SLOT( setOrientation( int ) ) ); 
52. } 
53.  
54. int main( int argc, char **argv ) 
55. { 
56.     QApplication a( argc, argv ); 
57.  
58.     MainWindow mainWindow; 
59.  
60.     mainWindow.resize( 600, 400 ); 
61.     mainWindow.show(); 
62.  
63.     return a.exec(); 
64. } 

barchart.h代码

1. #ifndef _BAR_CHART_H_ 
2.  
3. #include  
4.  
5. /**
6. *QwtPlotMultiBarChart显示一系列样本数据,每个样本由一组集合数据组成。
7. * 每一个数据都可以显示成一个直方图，当然每一组形成的直方图，既可以并排显示，也可以累加显示。
8. * 每一个集合的直方图，都可以用QwtColumnSymbol修饰
9. */ 
10. class QwtPlotMultiBarChart; 
11.  
12. class BarChart: public QwtPlot 
13. { 
14.     Q_OBJECT 
15.  
16. public: 
17.     BarChart( QWidget * = NULL ); 
18.  
19. public Q_SLOTS: 
20.     void setMode( int ); 
21.     void setOrientation( int ); 
22.     void exportChart(); 
23.  
24. private: 
25.     void populate(); 
26.  
27.     QwtPlotMultiBarChart *d_barChartItem; 
28. }; 
29.  
30. #endif 

barchat.cpp代码

1. #include "barchart.h" 
2. #include  
3. #include  
4. #include  
5. #include  
6. #include  
7. #include  
8. #include  
9.  
10. BarChart::BarChart( QWidget *parent ): 
11.     QwtPlot( parent ) 
12. { 
13.     setAutoFillBackground( true ); 
14.  
15.     setPalette( Qt::white ); 
16.     canvas()->setPalette( QColor( "LemonChiffon" ) ); 
17.  
18.     setTitle( "Bar Chart" ); 
19.  
20.     setAxisTitle( QwtPlot::yLeft, "Whatever" ); 
21.     setAxisTitle( QwtPlot::xBottom, "Whatever" ); 
22.  
23.     d_barChartItem = new QwtPlotMultiBarChart( "Bar Chart " ); 
24.     d_barChartItem->setLayoutPolicy( QwtPlotMultiBarChart::AutoAdjustSamples   ); 
25.     d_barChartItem->setSpacing( 20 );//spacing 是两个样本之间的距离（两个直方图之间的距离，或者每组直方图之间的距离 
26.     d_barChartItem->setMargin( 3);// margin 最外层的直方图与画布的边框矩形之间的距离 
27.  
28.     d_barChartItem->attach( this ); 
29.  
30.     insertLegend( new QwtLegend() );//插入描述符 
31.  
32.     populate(); 
33.     setOrientation( 0 ); 
34.  
35.     setAutoReplot( true ); 
36. } 
37.  
38. void BarChart::populate() 
39. { 
40.     static const char *colors[] = { "DarkOrchid", "SteelBlue", "Gold" }; 
41.  
42.     const int numSamples = 5; 
43.     const int numBars = sizeof( colors ) / sizeof( colors[0] ); 
44.  
45.     QList titles; 
46.     for ( int i = 0; i < numBars; i++ ) 
47.     { 
48.         QString title("Bar %1"); 
49.         titles += title.arg( i ); 
50.     } 
51.     d_barChartItem->setBarTitles( titles );//统一设置直方图的标题，这些标题是给legend用的 
52.     d_barChartItem->setLegendIconSize( QSize( 10, 14 ) ); 
53.  
54.     for ( int i = 0; i < numBars; i++ ) 
55.     { 
56.         QwtColumnSymbol *symbol = new QwtColumnSymbol( QwtColumnSymbol::Box ); 
57.         symbol->setLineWidth( 1 );//设置这个Box的边框宽度 
58.         symbol->setFrameStyle( QwtColumnSymbol::Plain  );//或者Raised 和NoFrame 
59.         symbol->setPalette( QPalette( colors[i] ) ); 
60.  
61.         d_barChartItem->setSymbol( i, symbol );//每一组内部的直方图设置 
62.     } 
63.      
64.     QVector< QVector<double> > series;//二维数据 
65.     for ( int i = 0; i < numSamples; i++ )//所有样本（直方图组） 
66.     { 
67.         QVector<double> values; 
68.         for ( int j = 0; j < numBars; j++ )//每组内的直方图赋值 
69.             values += ( 2 + qrand() % 8 ); 
70.  
71.         series += values; 
72.     } 
73.  
74.     d_barChartItem->setSamples( series ); 
75. } 
76. //设置直方图显示方式 
77. void BarChart::setMode( int mode ) 
78. { 
79.     if ( mode == 0 ) 
80.     { 
81.         d_barChartItem->setStyle( QwtPlotMultiBarChart::Grouped ); 
82.     } 
83.     else 
84.     { 
85.         d_barChartItem->setStyle( QwtPlotMultiBarChart::Stacked ); 
86.     } 
87. } 
88. //设置直方图显示方向和坐标轴变化 
89. void BarChart::setOrientation( int orientation ) 
90. { 
91.     QwtPlot::Axis axis1, axis2; 
92.  
93.     if ( orientation == 0 ) 
94.     { 
95.         axis1 = QwtPlot::xBottom; 
96.         axis2 = QwtPlot::yLeft; 
97.  
98.         d_barChartItem->setOrientation( Qt::Vertical ); 
99.     } 
100.     else 
101.     { 
102.         axis1 = QwtPlot::yLeft; 
103.         axis2 = QwtPlot::xBottom; 
104.  
105.         d_barChartItem->setOrientation( Qt::Horizontal ); 
106.     } 
107.     //设置x轴刻度 
108.     setAxisScale( axis1, 0, d_barChartItem->dataSize() - 1, 1.0 ); 
109.     //设置y周刻度自动调整 
110.     setAxisAutoScale( axis2 ); 
111.  
112.     //Backbone = the line where the ticks are located.    Ticks    Labels 
113.     //重新绘制坐标轴刻度 
114.     QwtScaleDraw *scaleDraw1 = axisScaleDraw( axis1 ); 
115.     scaleDraw1->enableComponent( QwtScaleDraw::Backbone, false ); 
116.     scaleDraw1->enableComponent( QwtScaleDraw::Ticks, false ); 
117.     QwtScaleDraw *scaleDraw2 = axisScaleDraw( axis2 ); 
118.  
119.     scaleDraw2->enableComponent( QwtScaleDraw::Backbone, true ); 
120.     scaleDraw2->enableComponent( QwtScaleDraw::Ticks, true ); 
121.     scaleDraw2->enableComponent( QwtScaleDraw::Labels , true ); 
122.  
123.  
124.  
125.  
126.     plotLayout()->setAlignCanvasToScale( axis1, true ); 
127.     plotLayout()->setAlignCanvasToScale( axis2, false ); 
128.  
129.     plotLayout()->setCanvasMargin( 0 ); 
130.     updateCanvasMargins(); 
131.  
132.     replot(); 
133. } 
134.  
135. void BarChart::exportChart() 
136. { 
137.     QwtPlotRenderer renderer; 
138.     renderer.exportTo( this, "barchart.pdf" ); 
139. }