On Thu, 26 Jun 2008, in microsoft.public.excel.charting,
said:
Unfortunately it's not as simple as that. While the data ranges
covered are the same, the data points within the ranges do not match
up across the ranges, hence the interpolation calculations being done
at the moment.

The important thing to realise is that this is not an Excel charting
question. Interpolation calculations are a matter of algebra. All Excel
Chart does is display points you give it via spreadsheet cells, and join
them up with lines. Any calculations you do would be the same whether
you were charting the result or not, so the posters here can't help you
except in so far as they may by chance know something about excel
functions. You're really better off asking in
microsoft.public.excel.worksheet.functions where the real function
experts are.

--
Del Cotter
NB Personal replies to this post will send email to ,
which goes to a spam folder-- please send your email to del3 instead.