在iOS的核心图中设置轴线

Question

I am plotting a bar graph using core plot for both positive and negative values.I want a line at x=0 seperating the positive and negative values .Can anyone tell me how to set the axis line

thanks

Answer 1

You need to set the orthogonalCoordinateDecimal property of the axes. So for example:

        yAxis.orthogonalCoordinateDecimal = CPTDecimalFromDouble(0); 

will make 0 the point of the yAxis where the yAxis crosses the xAxis.

Answer 2

In addition to using the orthogonalCoordinateDecimal as @pe60t0 mentioned, set the plot range of the y-axis so it covers both positive and negative values. For example to make the y-axis span from -10 to 10,

plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(-10.0)
                                                length:CPTDecimalFromDouble(20.0)];