ChartDirector 7.1 (C++ Edition)

Multiple Axes




This example demonstrates using 4 y-axes in a chart.

The 4 axes are the default primary and secondary y-axes at the left and right edges of the plot area, and two other y-axes added using XYChart.addAxis.

Layer.setUseYAxis and Layer.setUseYAxis2 are used to bind the line layers to the axes. Axis.setTitle and TextBox.setAlignment are used to set the axis titles and put them on the top of the axes. Axis.setColors is used to set the axis colors to be the same as the corresponding line layers for easy matching.

Source Code Listing

The following is the command line version of the code in "cppdemo/multiaxes". The MFC version of the code is in "mfcdemo/mfcdemo". The Qt Widgets version of the code is in "qtdemo/qtdemo". The QML/Qt Quick version of the code is in "qmldemo/qmldemo".
#include "chartdir.h" int main(int argc, char *argv[]) { // Data for the chart double data0[] = {1700, 3900, 2900, 3800, 4100, 4600, 2900, 4100, 4400, 5700, 5900, 5200, 3700, 3400, 5100, 5600, 5600, 6000, 7000, 7600, 6300, 6700, 7500, 6400, 8800}; const int data0_size = (int)(sizeof(data0)/sizeof(*data0)); double data1[] = {500, 550, 670, 990, 820, 730, 800, 720, 730, 790, 860, 800, 840, 680, 740, 890, 680, 790, 730, 770, 840, 820, 800, 840, 670}; const int data1_size = (int)(sizeof(data1)/sizeof(*data1)); double data2[] = {46, 68, 35, 33, 38, 20, 12, 18, 15, 23, 30, 24, 28, 15, 21, 26, 46, 42, 38, 25, 23, 32, 24, 20, 25}; const int data2_size = (int)(sizeof(data2)/sizeof(*data2)); double data3[] = {0.84, 0.82, 0.82, 0.38, 0.25, 0.52, 0.54, 0.52, 0.38, 0.51, 0.46, 0.29, 0.5, 0.55, 0.47, 0.34, 0.52, 0.33, 0.21, 0.3, 0.25, 0.15, 0.18, 0.22, 0.14}; const int data3_size = (int)(sizeof(data3)/sizeof(*data3)); // Labels for the chart const char* labels[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24"}; const int labels_size = (int)(sizeof(labels)/sizeof(*labels)); // Create a XYChart object of size 600 x 360 pixels. Use a vertical gradient color from sky blue // (aaccff) to white (ffffff) as background. Set border to grey (888888). Use rounded corners. // Enable soft drop shadow. XYChart* c = new XYChart(600, 360); c->setBackground(c->linearGradientColor(0, 0, 0, c->getHeight(), 0xaaccff, 0xffffff), 0x888888); c->setRoundedFrame(); c->setDropShadow(); // Add a title box to the chart using 15pt Arial Bold Italic font. Set top margin to 16 pixels. TextBox* title = c->addTitle("Multiple Axes Demonstration", "Arial Bold Italic", 15); title->setMargin(0, 0, 16, 0); // Set the plotarea at (100, 80) and of size 400 x 230 pixels, with white (ffffff) background. // Use grey #(aaaaa) dotted lines for both horizontal and vertical grid lines. c->setPlotArea(100, 80, 400, 230, 0xffffff, -1, -1, c->dashLineColor(0xaaaaaa, Chart::DotLine), -1); // Add a legend box with the bottom center anchored at (300, 80) (top center of the plot area). // Use horizontal layout, and 8 points Arial Bold font. Set background and border to // transparent. LegendBox* legendBox = c->addLegend(300, 80, false, "Arial Bold", 8); legendBox->setAlignment(Chart::BottomCenter); legendBox->setBackground(Chart::Transparent, Chart::Transparent); // Set the labels on the x axis. c->xAxis()->setLabels(StringArray(labels, labels_size)); // Display 1 out of 3 labels on the x-axis. c->xAxis()->setLabelStep(3); // Add a title to the x-axis c->xAxis()->setTitle("Hour of Day"); // Add a title on top of the primary (left) y axis. c->yAxis()->setTitle("Power\n(Watt)")->setAlignment(Chart::TopLeft2); // Set the axis, label and title colors for the primary y axis to red (c00000) to match the // first data set c->yAxis()->setColors(0xcc0000, 0xcc0000, 0xcc0000); // Add a title on top of the secondary (right) y axis. c->yAxis2()->setTitle("Load\n(Mbps)")->setAlignment(Chart::TopRight2); // Set the axis, label and title colors for the secondary y axis to green (00800000) to match // the second data set c->yAxis2()->setColors(0x008000, 0x008000, 0x008000); // Add the third y-axis at 50 pixels to the left of the plot area Axis* leftAxis = c->addAxis(Chart::Left, 50); // Add a title on top of the third y axis. leftAxis->setTitle("Temp\n(C)")->setAlignment(Chart::TopLeft2); // Set the axis, label and title colors for the third y axis to blue (0000cc) to match the third // data set leftAxis->setColors(0x0000cc, 0x0000cc, 0x0000cc); // Add the fouth y-axis at 50 pixels to the right of the plot area Axis* rightAxis = c->addAxis(Chart::Right, 50); // Add a title on top of the fourth y axis. rightAxis->setTitle("Error\n(%)")->setAlignment(Chart::TopRight2); // Set the axis, label and title colors for the fourth y axis to purple (880088) to match the // fourth data set rightAxis->setColors(0x880088, 0x880088, 0x880088); // Add a line layer to for the first data set using red (c00000) color, with a line width of 2 // pixels LineLayer* layer0 = c->addLineLayer(DoubleArray(data0, data0_size), 0xcc0000, "Power"); layer0->setLineWidth(2); // Add a line layer to for the second data set using green (00c0000) color, with a line width of // 2 pixels. Bind the layer to the secondary y-axis. LineLayer* layer1 = c->addLineLayer(DoubleArray(data1, data1_size), 0x008000, "Load"); layer1->setLineWidth(2); layer1->setUseYAxis2(); // Add a line layer to for the third data set using blue (0000cc) color, with a line width of 2 // pixels. Bind the layer to the third y-axis. LineLayer* layer2 = c->addLineLayer(DoubleArray(data2, data2_size), 0x0000cc, "Temperature"); layer2->setLineWidth(2); layer2->setUseYAxis(leftAxis); // Add a line layer to for the fourth data set using purple (880088) color, with a line width of // 2 pixels. Bind the layer to the fourth y-axis. LineLayer* layer3 = c->addLineLayer(DoubleArray(data3, data3_size), 0x880088, "Error Rate"); layer3->setLineWidth(2); layer3->setUseYAxis(rightAxis); // Output the chart c->makeChart("multiaxes.png"); //free up resources delete c; return 0; }