Question

I am using Reportlab to create some graphs in my PDF reports. I was creating an Area Line Plot and got stuck at a point where I am not able to understand why am I not getting the output I would like to see.

Here is the code I had written for my output:

def standardLinePlot(data, width=200, height=200):

    d = Drawing(width, height)
    lp = AreaLinePlot()
    lp.data=data
    lp.width, lp.height = width, height
    lp.xValueAxis.valueMin = 0
    lp.xValueAxis.valueMax =36
    lp.xValueAxis.valueSteps = [0,6,12,18,24,30,36]

    lp.yValueAxis.valueMin = 0
    lp.yValueAxis.valueMax =100

    lp.strokeColor=colors.black
    lp.fillColor=colors.grey

    lp.reversePlotOrder = False

    lp.joinedLines=1

    d.add(lp)

    return d

The output I am getting is:

My intended output is that grey color should be in place of red color which is the area under the line plot. The other problem is how can I add the axis title to this chart. For example, I need “Months” to be my X axis and “% of NAV” to be my Y axis.

Answer 1

To define the color for the lines it seems you need to access… well, the lines :). So, lp.lines[0].strokeColor = colors.grey instead of lp.strokeColor = colors.grey, as that one goes for the plot background color!

The question about the labels is a bit more tricky, though… ScatterPlot includes functionality to set labels for X and Y axis, but that’s not the case for AreaLinePlot. Of course, you could derive a class from AreaLinePlot copying that functionality, if you’re going to use it often.