Logarithm equation in charts

[Thiem]

I have two lists of data. One is a time series, other data series. I
can calculate the Linear equation , same as in the excel graph, if I
insert trend lines, but I can workout the LOG trendline equation as
displayed in the graph. Could someone assist, or tel me how to export
the equition from the graph to an cell in excel.

Please advise

TX


AT

 

[MrShorty]

Have you tried LOGEST() or GROWTH() worksheet functions?

 

[Mike Middleton]

Thiem

I have two lists of data. One is a time series, other data series. I can
calculate the Linear equation , same as in the excel graph, if I insert
trend lines, but I can workout the LOG trendline equation as displayed in
the graph. Could someone assist, or tel me how to export the equition from
the graph to an cell in excel. Please advise <

Using Excel's notation, the log trendline uses the equation Y = c*Ln(X)+b.

c = SLOPE(Yrange,LN(Xrange))
b = INTERCEPT(Yrange,LN(Xrange))

Tushar Mehta's web site www.tushar-mehta.com shows how to get the same
results using the array-entered worksheet function =LINEST(y-range,
LN(x-range)).

- Mike
www.mikemiddleton.com