(This works for me using Excel 97 under Windows XP)
Consider the following range
Series1
1 4
2 2
3 8
4 4
5 7
6 9
7 5
8 6
Where the label "Series1" occupies the cell B2, the X range is A2..A9
and the Y range is B2..B9. If you quickly use the Chart Wizard to create
a scatter chart with lines and markers, the Source Data will look like
this:
X Values: =Sheet1!$A$2:$A$9
Y Values: =Sheet1!$B$2:$B$9
So far, nothing surprising. Now if you go in and manually edit the range
(first remembering that F2 key!) so it looks like this:
X Values: =Sheet1!$A$2:$A$9,Sheet1!$A$2:$A$9
Y Values: =Sheet1!$B$2:$B$9,Sheet1!$B$2:$B$9
(i.e. the same ranges copied twice and separated by a comma)
nothing changes on the scatter graph, except that there is now a line
zipping back to the beginning: the data is just being drawn twice.
Now go in and manually edit the range again so it looks like this:
X Values: =(Sheet1!$A$3:$A$9,Sheet1!$A$2:$A$9)
Y Values: =(Sheet1!$B$2:$B$8,Sheet1!$B$2:$B$9)
(i.e. the X range first part has lost its first row cell, and the Y
range first part has lost its last row cell)
the scatter chart now looks like it has double vision: The line is drawn
across the chart, zips back, and draws itself again displaced one place
to the left.
Now change the chart type to Line, and change the X axis to Time-scale,
and see what you get.
!!
How does it work? Whereas the line in a scatter chart is drawn strictly
in the order the data points appear in the range, the line in a
Time-scale Line chart is drawn from left to right in the order the
points appear on the time-scale!
I expect somebody who knows VBA could turn this into a macro.