Trend Line Values In Excel

[sir_william]

I am an analyst at an Oil company. We plot hyperbolic decline production curves in excel, however I am wondering if there is a way to collect the values that are based on the trendline curve. The thought of this is to use these data values as a sort of interpolation curve for errors in the data.

Does anyone know how to extract the values that a trenline is made up of?

 

[a7n9]

If you're using the trendlines from Excel on a scatter plot, then just select the trendline from the plot, right click>>Format Trendline>>Go to Options>>Check the box for "Display equation on Chart"

Hope this helps

 

[sir_william]

Well, that helps in a way.

I was hoping that the simplicity of the trendline was represented in excel by *creating a virtual array of numbers based on that equation that I could extract then drop in column B (where the source data would be in column A, rather than Excel drawing a curve from a mathmatical calculation.

This makes sense though... but still wish that there would be an option to convert that trend equation to raw numbers in an array for me that I could simply copy without further computation.

 

[a7n9]

There are functions like: LINEST (linear), LOGEST (Exponential), TREND (to predict). However, it cannot calculate hyperbolic trendline function, in my knowledge.

Also, you can copy that equation from the chart and put in column B, then all you have to change is the X and Y

If you know the algorithm of fitting Hyperbolic, we can try to create that function.

Check these links at MS:
http://office.microsoft.com/en-us/assistance/HA011118881033.aspx
http://office.microsoft.com/en-us/assistance/HA011416701033.aspx
http://office.microsoft.com/en-us/assistance/HA010929231033.aspx