How did Apple define a line graph X axis without a header column?

flyleaf wrote:

Apple set the X-axis values for their line graph using a column that is not defined as a header column.

When I try to create a line graph myself from a table without a header column, I can't seem to define the X axis at all. But Apple did it. How?

On the Mac I selected columns B and C in the data table in the 'Break-Even Analysis' template and inserted a Line Chart. No x-axis labels.

But on the Mac you can add them "after the fact" by doing something like this:

1. Click the chart and go to Axis > Category (X) tab.
2. Click 'Label References' entry, select all the contents there ("Untitled 1","Untitled 2","Untitled 3"....), and click the A column letter in the table (thus selecting that entire column)
3. Accept that by clicking the checkmark, and the x-axis labels will appear, even though column A is not a Header Column.

When opening that document on the iPad the settings are respected. Since there appears to be no similar way to add x-axis labels "after the fact" on the iPad, I am guessing that may have been what Apple did.

Of course simply defining a Header Column for that data table on the iPad, selecting columns A thru C (i.e. including the Header Column) and inserting a Line Chart achieves the same result, with less effort.

SG

On the Mac version it is easy to choose a non-header column/row as the X axis labels after a chart is created. I tried doing it my phone but found no place to enter the range for the labels. I did not try the iCloud version.

I wonder what would happen in the iOS version if you added new data to the bottom of the table and tried to include it in the chart. It might not pick up the new X axis labels unless the original range for the labels was the entire column A versus the range A2:A22

Another idea for the chart you showed is to use a scatter chart. A scatter chart is a true X-Y chart and the X axis data must be in a regular column/row; it cannot be in a header column/row.

When you tap the "Gear" upper right have you selected Plot Columns as Series?

If you do that, then Numbers will pick up the labels from the Header Row and show them on the x-axis.

SG