Plot a Graph without data Column?

I have a table with two columns. One is actual length (La), the other is given length (Lg). I want to plot a graph with '% Error' vs. 'given length (Lg)' without adding column for '% difference in length'.

The equation for % difference = [La-Lg]/Lg

Can I write a macro which counts the % difference from the given data and plot it vs. Lg without the % diff. column? I use this plot as a check for any typographical errors, so I don't need to save the graph.

Is it possible? Thanks.

I have attached the sample file. (Actual xls sheet is much more complicated.)

Originally Posted by Andy Pope

Yes using named ranges.

See attached I have added a series based on named ranges.

That is exactly what I want. But where is that named range. How can I see it? I mean PERC ERROR name range.

Never mind. I found it. It was in define names, right?

Thanks a lot....