How can I make the X axis temporally proportional?

There may be some way to build a customized axis scale and plot that, but the easiest way for me is to pick the "scatter" chart type in the inspector and Connect Points (either Curve or Straight) as shown here:

You can use an X-Y scatter chart:

Hi c,

The Line chart (like most of the other chart types) is a Category chart, and spaces the categories evenly along the Category axis.

The only exception to the Category types is the Scatter Chart, in which both the X and Y axes are Value axes. As both previous posters have said, that's the type of chart to use for your desied result

One other difference to be aware of: For Category charts, the Categories are usually listed in a Header column, where Numbers can pick them up and automatically appply them as Category Labels; for a scatter chart, the values come in pairs, and both items in each pair must be in regular body columns.

Regards,

Barry

Look forward to the real experts' comments on chart overlays.

As for date-format for X-axis it took some fiddling for me (sometimes it was greyed out) but it does work.

Either leave it as Same as Source Data or pick Date and Time and choose one of the many formats available, some shorter than the source data format.

I haven't figured out how to make specific dates show up on the axis, e.g. in my example it would be nicer to show mid-month and/or month-end dates. Numbers seems to split into intervals based on the number of Steps, with little (no?) control over where intervals begin/end.

CB,

Yes, you can overlay charts, like any graphics.

Date values are valid for either axis in Scatter chart. Just make sure that both columns are non-Header, and formatted appropriately.

Jerry

"Can I overlay two charts on the same set of axes?"

You can overlay charts, as Jerry has already stated.

You can also, it both X and Y data are comparable, place the two plots onto the same chart.

Regards,

Barry