Extracting out the trendline from a log curve fit

[mp16]

Does anyone know how, given a data set, I can pull out the equation of the trendline without having to plot the chart and visually type in the code?
I have to perform this and build up equations for best fits for around 500 data arrays - so am in great need for an automated process. I dont believe the data anlaysis regression tool would also be suited (unless there is a way of accesing this from VBA which I am not aware of).

I would appreciate your help.

Many thanks,
Tanveer.

[TheRobster]

What's the reason you can't just do it in Excel and use the built-in regression analysis function?

[mp16]

Hi,
I dont know how this is possible? which function are you referring to? Using data analysis tool pack, it creates a matrix - and I dont think its a good idea to generate matrix data for 500 names?
Is this do-able in VBA? any sources of reference will be appreciated.

Thanks

[TheRobster]

I could be misunderstanding the type of data you're dealing with here - I thought the data was the type with x-y coordinates that you could just plot on a standard pair of axis, with a relationship existing between x and y

i.e. y = some function of x

If so then excel can find the equations for such graphs.......if you're dealing with a different sort of data then sorry but I don't know how you'd do it.

[mp16]

Yes I have 500 sets of X-Y data, and for each data set I need to extract out the function of the polynomial fit along with the R2 value.
I need this to be done without generating excessive data in the form that the regression tool pack gives.

Does this help clarify the problem I face?

Cheers.

[TheRobster]

Can you post a download link to some (or all) of the data in either an Excel or ASCII format so I can have an attempt at doing it in Excel?

Or is it classified information?

[yrwyddfa]

http://www.vbforums.com/showthread.p...hreadid=311225