Question

I would like to make a plot where the second x and y axis are simply a mirror of the primary axis. For example like this typical scientific style plot with the inner facing tick marks,
.

It this easy to accomplish with coreplot?

Answer 1

Create two new axes, one for x and one for y. Configure them to match the other axes, except change the tickDirection to point the other way and position them at the opposite side of the graph (using the orthogonalCoordinateDecimal or constraints). Assign both new axes to the same plot space used by the other axes. Add all four axes to an array and pass it to the axis set:

graph.axisSet.axes = [NSArray arrayWithObjects:x, y, x2, y2, nil];

There is an example of adding additional axes to a graph in the Plot Gallery demo app.