Core Plot graph bottom axis not visible

Question

I've got a core-plot line graph which is displaying as follows (background view coloured red for clarity):

I have 0 padding at the bottom, and I have an x-axis configured, with labels. The graph is squeezed right down against the bottom of the view though. If I increase the bottom padding I get a grey bar at the bottom with the same result.

What do I need to change in order to move the graph up from the bottom of the view and display the axis?

The code is quite lengthy, but here's some excerpts:

    self->graph = [[CPTXYGraph alloc] initWithFrame:hostView.bounds];
    hostView.hostedGraph = graph;
    self->graph.paddingLeft = 0.0f;
    self->graph.paddingTop = 10.0f;
    self->graph.paddingRight = 0.0f;
    self->graph.paddingBottom = 0.0f;

    ...

    [plotSpace scaleToFitPlots:[NSArray arrayWithObjects:p1, p2, p3, nil]];
    CPTMutablePlotRange *xRange = [plotSpace.xRange mutableCopy];
    [xRange expandRangeByFactor:CPTDecimalFromCGFloat(1.1f)];
    plotSpace.xRange = xRange;
    CPTMutablePlotRange *yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0f) length:CPTDecimalFromFloat(500.0f)];
    plotSpace.yRange = yRange;

    ...

    CPTXYAxisSet *axisSet = (CPTXYAxisSet *) self->graph.axisSet;
    CPTAxis *x = axisSet.xAxis;
    x.axisLineStyle = axisLineStyle;
    x.labelingPolicy = CPTAxisLabelingPolicyNone;
    x.majorTickLineStyle = axisLineStyle;
    x.majorTickLength = 4.0f;
    x.tickDirection = CPTSignNegative;

    ...

    x.axisLabels = xLabels;
    x.majorTickLocations = xLocations;

Answer 1

Try adding bottom padding to graph.plotAreaFrame.