ChartDirector Ver 3.0 (Python Edition)

Line with Error Symbols




The chart in the example is created by combining a line layer with a box-whisker layer.

The blue line and the yellow diamond symbols are from the line layer, creating using XYChart.addLineLayer2, Layer.addDataSet, and DataSet.setDataSymbol.

The brown error marks belong to the box-whisker layer, created using XYChart.addBoxWhiskerLayer. The data for the box and median parts of the box- whisker layer are set to empty arrays, so only the maximum and minimum marks are visible.

The maximum and minimum marks in this example is computed by adding/subtracting the error value to/from the data value using a ChartDirector utility class ArrayMath.

Source Code Listing

[File: pythondemo/errline.py] (The CGI version is available as "pythondemo_cgi/errline.py".)
#!/usr/bin/python from pychartdir import * #The data with error information data = [42, 49, 33, 38, 51, 46, 29, 41, 44, 57, 59, 52, 37, 34, 51, 56, 56, 60, 70, 76, 63, 67, 75, 64, 51] errData = [5, 6, 5.1, 6.5, 6.6, 8, 5.4, 5.1, 4.6, 5.0, 5.2, 6.0, 4.9, 5.6, 4.8, 6.2, 7.4, 7.1, 6.0, 6.6, 7.1, 5.3, 5.5, 7.9, 6.1] #The labels for the chart labels = ["0", "-", "-", "3", "-", "-", "6", "-", "-", "9", "-", "-", "12", "-", "-", "15", "-", "-", "18", "-", "-", "21", "-", "-", "24"] #Create a XYChart object of size 600 x 300 pixels, with a light grey (0xc0c0c0) #background, a black border, and 1 pixel 3D border effect. c = XYChart(600, 300, 0xc0c0c0, 0, 1) #Set the plotarea at (55, 45) and of size 520 x 205 pixels, with white #background. Turn on both horizontal and vertical grid lines with light grey #color (0xc0c0c0) c.setPlotArea(55, 45, 520, 210, 0xffffff, -1, -1, 0xc0c0c0, 0xc0c0c0) #Add a title box to the chart using 13 pts Arial Bold Italic font. The title is #in CDML and includes embedded images for highlight. The text is white #(0xffffff) on a black background, with a 1 pixel 3D border. c.addTitle( "<*block,valign=absmiddle*><*img=star.png*><*img=star.png*> Molecular " \ "Temperature Control <*img=star.png*><*img=star.png*><*/*>", "arialbi.ttf", 13, 0xffffff).setBackground(0x0, -1, 1) #Add a title to the y axis c.yAxis().setTitle("Temperature") #Add a title to the x axis using CMDL c.xAxis().setTitle( "<*block,valign=absmiddle*><*img=clock.png*> Elapsed Time (hour)<*/*>") #Set the labels on the x axis c.xAxis().setLabels(labels) #Set the axes width to 2 pixels c.xAxis().setWidth(2) c.yAxis().setWidth(2) #Add a line layer to the chart lineLayer = c.addLineLayer2() #Add a blue (0xff) data set to the line layer, with yellow (0xffff80) diamond #symbols lineLayer.addDataSet(data, 0xff).setDataSymbol(DiamondSymbol, 12, 0xffff80) #Set the line width to 2 pixels lineLayer.setLineWidth(2) #Add a box whisker layer to the chart. Use only the upper and lower mark of the #box whisker layer to act as error zones. The upper and lower marks are computed #using the ArrayMath object. errLayer = c.addBoxWhiskerLayer([], [], ArrayMath(data).add(errData).result(), ArrayMath(data).sub(errData).result(), [], Transparent, 0xbb6633) #Set the line width to 2 pixels errLayer.setLineWidth(2) #Set the error zone to occupy half the space between the symbols errLayer.setDataGap(0.5) #Add a custom CDML text at the bottom right of the plot area as the logo c.addText(575, 255, "<*block,valign=absmiddle*><*img=small_molecule.png*> <*block*>" \ "<*font=timesbi.ttf,size=10,color=804040*>Molecular\nEngineering<*/*>" ).setAlignment(BottomRight) #output the chart c.makeChart("errline.png")