Access to Chart Trendline Equations in VB
I would like to get the 3rd order polynomial coefficients for an X-Y Chart
trendline into VB so I can automatically run a calculation at a extrapolated X value and record this in my spreadsheet. If I can not get the coefficients directly to do the calculation myself, can I plug in the X value and calculate the resultant would help. |
Access to Chart Trendline Equations in VB
KMH wrote...
I would like to get the 3rd order polynomial coefficients for an X-Y Chart trendline into VB so I can automatically run a calculation at a extrapolated X value and record this in my spreadsheet. If I can not get the coefficients directly to do the calculation myself, can I plug in the X value and calculate the resultant would help. See http://groups.google.com/group/micro...440d271303e0d6 |
Access to Chart Trendline Equations in VB
Googling splines might be helpful to you.
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Access to Chart Trendline Equations in VB
If you just want the coefficients, you can use LINEST. Select a range 4
cells wide and five cells high. Type this equation: =LINEST(<yRange,<xRange^{1,2,3},TRUE,TRUE) where xRange and yRange are the addresses of the X and Y values, and array-enter the formula by holding CTRL+SHIFT while pressing ENTER. The first row of cells show the 3rd, 2nd, 1st, and 0th order coefficients of the poly fit. Check help for LINEST to learn what the rest of the LINEST output includes. - Jon ------- Jon Peltier, Microsoft Excel MVP Tutorials and Custom Solutions Peltier Technical Services, Inc. - http://PeltierTech.com _______ "Harlan Grove" wrote in message oups.com... KMH wrote... I would like to get the 3rd order polynomial coefficients for an X-Y Chart trendline into VB so I can automatically run a calculation at a extrapolated X value and record this in my spreadsheet. If I can not get the coefficients directly to do the calculation myself, can I plug in the X value and calculate the resultant would help. See http://groups.google.com/group/micro...440d271303e0d6 |
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