Trendline Equations

[swissforestry]

Hello~

Is there a way to have a cell state the "Trendline Equation" from a chart? I can get the chart to display the equation, but so far I have to manually input the formula to a cell if I want to use it. I would like to bypass this, so I don’t have to change the Equation if I change the data in the chart.

Alternatively, can you have a function that recognizes the variables in the equation, and just reference it from the chart? So in this case i would want to have a formula that would identify the trendline equation and also identify the x,y: i.e B4 = (X) and B5 = (y). Then i could drag it down the column for each row.

make any sense??

thanks~

[Gary''s Student]

Your question makes a lot of sense. Look for help on LINEST to see if it can
help you.
--
Gary''s Student


"swissforestry" wrote:

>
> Hello~
>
> Is there a way to have a cell state the "Trendline Equation" from a
> chart? I can get the chart to display the equation, but so far I have
> to manually input the formula to a cell if I want to use it. I would
> like to bypass this, so I don’t have to change the Equation if I change
> the data in the chart.
>
> Alternatively, can you have a function that recognizes the variables in
> the equation, and just reference it from the chart? So in this case i
> would want to have a formula that would identify the trendline equation
> and also identify the x,y: i.e B4 = (X) and B5 = (y). Then i could drag
> it down the column for each row.
>
> make any sense??
>
> thanks~
>
>
> --
> swissforestry
> ------------------------------------------------------------------------
> swissforestry's Profile: http://www.excelforum.com/member.php...o&userid=28719
> View this thread: http://www.excelforum.com/showthread...hreadid=489220
>
>

[Ron Rosenfeld]

On Tue, 29 Nov 2005 15:29:37 -0600, swissforestry
<[email protected]> wrote:

>
>Hello~
>
>Is there a way to have a cell state the "Trendline Equation" from a
>chart? I can get the chart to display the equation, but so far I have
>to manually input the formula to a cell if I want to use it. I would
>like to bypass this, so I don’t have to change the Equation if I change
>the data in the chart.
>
>Alternatively, can you have a function that recognizes the variables in
>the equation, and just reference it from the chart? So in this case i
>would want to have a formula that would identify the trendline equation
>and also identify the x,y: i.e B4 = (X) and B5 = (y). Then i could drag
>it down the column for each row.
>
>make any sense??
>
>thanks~

If you have Excel 2003, you can probably use the LINEST worksheet function
safely. It is available in earlier versions, but others have written that the
algorithm is not as robust in earlier versions.

David Braden posted some VBA code a few years ago that can extract the
coefficients from a chart. The chart trendline algorithm is different from the
LINEST algorithm, and is felt by others to be quite stable. See:

http://groups.google.com/groups?selm....microsoft.com

or

http://groups.google.com/group/micro...440d271303e0d6

or

http://tinyurl.com/8ozq9


--ron