ExcelBanter

ExcelBanter (https://www.excelbanter.com/)
-   Excel Discussion (Misc queries) (https://www.excelbanter.com/excel-discussion-misc-queries/)
-   -   Trend Line Equation Coefficients (https://www.excelbanter.com/excel-discussion-misc-queries/83569-trend-line-equation-coefficients.html)

Jake

Trend Line Equation Coefficients
 
Is there a way to link to the coefficients of a trend line? I have some data
plotted with a exponential trend line fitted to it and the equation of the
trend line (y = cx^d) shown on the chart. Rather than manually copying c and
d to use them in another worksheet, I would like to link to them so that I
don't have to re-copy everytime my data changes. Can this be done?

Thanks.

Bernard Liengme

Trend Line Equation Coefficients
 
If you really are using an exponential fit < y=Aexp(Bx) see
http://www.stfx.ca/people/bliengme/E...&%20LOGEST.htm
If you are using a power fit < y = Ax^B then see the lower half of
http://www.stfx.ca/people/bliengme/E...Polynomial.htm
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Jake" wrote in message
...
Is there a way to link to the coefficients of a trend line? I have some
data
plotted with a exponential trend line fitted to it and the equation of the
trend line (y = cx^d) shown on the chart. Rather than manually copying c
and
d to use them in another worksheet, I would like to link to them so that I
don't have to re-copy everytime my data changes. Can this be done?

Thanks.




Jake

Trend Line Equation Coefficients
 
Cool, thanks. You're right - it's power fit, not exponential.

"Bernard Liengme" wrote:

If you really are using an exponential fit < y=Aexp(Bx) see
http://www.stfx.ca/people/bliengme/E...&%20LOGEST.htm
If you are using a power fit < y = Ax^B then see the lower half of
http://www.stfx.ca/people/bliengme/E...Polynomial.htm
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Jake" wrote in message
...
Is there a way to link to the coefficients of a trend line? I have some
data
plotted with a exponential trend line fitted to it and the equation of the
trend line (y = cx^d) shown on the chart. Rather than manually copying c
and
d to use them in another worksheet, I would like to link to them so that I
don't have to re-copy everytime my data changes. Can this be done?

Thanks.





Jake

Trend Line Equation Coefficients
 
Actually, using this method gives me slightly different coefficients than the
numbers I got from the excel trendline equation. Any idea why?

Trendline:
a = 0.011
b = -0.433

Linest Equation
a = 0.014
b = -0.453

I only have 5 data points so might as well share those too:
1, 1.0985%
2, 0.7889%
3, 0.6603%
4, 0.6036%
5, 0.5432%



"Jake" wrote:

Is there a way to link to the coefficients of a trend line? I have some data
plotted with a exponential trend line fitted to it and the equation of the
trend line (y = cx^d) shown on the chart. Rather than manually copying c and
d to use them in another worksheet, I would like to link to them so that I
don't have to re-copy everytime my data changes. Can this be done?

Thanks.


Bernard Liengme

Trend Line Equation Coefficients
 
My LINEST values are -0.4334173337 -4.5248442752

So my coefficients are
-0.4334173337 0.010836402

which are identical to those in the trendline equation.
I am using Excel 2003, what version are you using?
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Jake" wrote in message
...
Actually, using this method gives me slightly different coefficients than
the
numbers I got from the excel trendline equation. Any idea why?

Trendline:
a = 0.011
b = -0.433

Linest Equation
a = 0.014
b = -0.453

I only have 5 data points so might as well share those too:
1, 1.0985%
2, 0.7889%
3, 0.6603%
4, 0.6036%
5, 0.5432%



"Jake" wrote:

Is there a way to link to the coefficients of a trend line? I have some
data
plotted with a exponential trend line fitted to it and the equation of
the
trend line (y = cx^d) shown on the chart. Rather than manually copying c
and
d to use them in another worksheet, I would like to link to them so that
I
don't have to re-copy everytime my data changes. Can this be done?

Thanks.





All times are GMT +1. The time now is 11:32 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
ExcelBanter.com