graphing inconsistent dates and calculating "best fit" data

[gconner]

Hi, I hope u guys (and girls) can help.
I am making a scrolling graph (that is not the hard part).

The problem is that usually i have a date value and measurement value for every day but sometimes there may be a few days missing, even up to periods of 2 weeks. Using the Match or Vookup fuctions dont really do what i am after.

if i want to show exactly one month of data on the graph, is there a way i can "fill in the missing dates" and still calculate a value during periods where the data is missing, using the date values either side of the one I am trying to show on the graph???

Any help would be appreciated!!!

[MrShorty]

There are usually two ways to do this -- an interpolation algorithm where you assume each known point is connected by straight lines, and use those straight lines to fill in the uknown points, or a regression algorithm where you fit the entire month's worth of data to a single equation, then use that equation to fill in the missing points. Which method would you like to use?