Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
acjim
 
Posts: n/a
Default Excel Function to Match Power Trendline in Chart?


Hi,

I'm using the "Power" trendline in an XY scatter chart and want to use
the formula and the rsquared result in a worksheet.

What worksheet function can I use to to show the function (or it's
components) and the rsquared within the worksheet?

(The formula stated on the chart is: y = 644.691x^-0.895)

I've looked at LINEST but that seems to only give a straight line
trend?

LOGEST gives me the exponential result?

Basically I'm worried about using the rsquared value from the chart if
I don't have it through a function as well.

Anyone able to help?

Thanks!


--
acjim
------------------------------------------------------------------------
acjim's Profile: http://www.excelforum.com/member.php...o&userid=24487
View this thread: http://www.excelforum.com/showthread...hreadid=381152

  #2   Report Post  
Jerry W. Lewis
 
Posts: n/a
Default

Despite extremely misleading text in Help, LINEST is not limited to
straight lines; it fits models that are linear in the unknown
coefficients (polynomials, etc.), cf.
http://www.stfx.ca/people/bliengme/E...Polynomial.htm
If y=a*x^b then ln(y)=ln(a)+b*ln(x), which the chart trendline uses to
estimate the coefficients. In that second form, you can use LINEST, or
SLOPE, INTERCEPT, and RSQ. If you do not have Excel 2003,
http://groups-beta.google.com/group/...e7a1c650?hl=en
suggests alternate calculations that will be more accurate in certain
circumstances.

Jerry

acjim wrote:

Hi,

I'm using the "Power" trendline in an XY scatter chart and want to use
the formula and the rsquared result in a worksheet.

What worksheet function can I use to to show the function (or it's
components) and the rsquared within the worksheet?

(The formula stated on the chart is: y = 644.691x^-0.895)

I've looked at LINEST but that seems to only give a straight line
trend?

LOGEST gives me the exponential result?

Basically I'm worried about using the rsquared value from the chart if
I don't have it through a function as well.

Anyone able to help?

Thanks!


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fan charts Dean Charts and Charting in Excel 7 May 30th 05 11:51 AM
CHR() function not working in Excel 2003 Richard Jonas Excel Discussion (Misc queries) 4 February 16th 05 08:45 AM
Adding a chart to a Word template linked to an Excel doc. Bobbie Excel Discussion (Misc queries) 0 January 3rd 05 08:07 PM
Import chart to Power Point and Macro problem Woody13 Excel Discussion (Misc queries) 1 December 8th 04 05:47 PM
Excel function help facilities RPS Excel Discussion (Misc queries) 1 December 8th 04 02:36 AM


All times are GMT +1. The time now is 11:36 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 ExcelBanter.
The comments are property of their posters.
 

About Us

"It's about Microsoft Excel"