ChartDirector 7.0 (Python Edition)

Vector Chart




This example demonstrates a vector chart.

A vector chart is like a scatter chart, but the symbols are arrows which can be of arbitrary lengths pointing to arbitrary directions. Thus each symbol in a vector chart is specified by 4 values - the x and y coordinates, the length and the direction.

In ChartDirector, an XY vector layer is created using XYChart.addVectorLayer.

Source Code Listing

pythondemo\vector.py
#!/usr/bin/python # The ChartDirector for Python module is assumed to be in "../lib" import sys, os sys.path.insert(0, os.path.join(os.path.abspath(sys.path[0]), "..", "lib")) from pychartdir import * # The (x, y) coordinates of the starting point of the vectors dataX = [20, 40, 60, 80, 100, 20, 40, 60, 80, 100, 20, 40, 58, 62, 80, 100, 20, 40, 60, 80, 100, 20, 40, 60, 80, 100] dataY = [20, 20, 20, 20, 20, 40, 40, 40, 40, 40, 60, 60, 60, 60, 60, 60, 80, 80, 80, 80, 80, 100, 100, 100, 100, 100] # The lengths (radii) and directions (angles) of the vectors dataR = [6, 6, 9, 6, 6, 6, 9, 12, 9, 6, 9, 12, 12, 12, 12, 9, 6, 9, 12, 9, 6, 6, 6, 9, 6, 6] dataA = [-45, -30, 0, 30, 45, -60, -45, 0, 45, 60, -90, -90, -90, 90, 90, 90, -120, -135, 180, 135, 120, -135, -150, 180, 150, 135] # Create a XYChart object of size 450 x 390 pixels c = XYChart(450, 390) # Set the plotarea at (55, 40) and of size 350 x 300 pixels, with a light grey border (0xc0c0c0). # Turn on both horizontal and vertical grid lines with light grey color (0xc0c0c0) c.setPlotArea(55, 40, 350, 300, -1, -1, 0xc0c0c0, 0xc0c0c0, -1) # Add a title to the chart using 18pt Times Bold Itatic font. c.addTitle("Vector Chart Demonstration", "Times New Roman Bold Italic", 18) # Add a title to the y axis using 12pt Arial Bold Italic font c.yAxis().setTitle("Y Axis Title", "Arial Bold Italic", 12) # Add a title to the x axis using 12pt Arial Bold Italic font c.xAxis().setTitle("X Axis Title", "Arial Bold Italic", 12) # Set the axes line width to 3 pixels c.xAxis().setWidth(3) c.yAxis().setWidth(3) # Add a vector layer to the chart using blue (0000CC) color, with vector arrow size set to 11 pixels c.addVectorLayer(dataX, dataY, dataR, dataA, YAxisScale, 0x0000cc).setArrowHead(11) # Output the chart c.makeChart("vector.png")