Displaying 1 result from an estimated 1 matches for "exponcycles".
2009 Dec 01
2
Starting estimates for nls Exponential Fit
...'good estimates' do
not work. I am desperatly seeking a way of calculating working starting
estimates for my nls function. Can anybody give me a hand?
thanks,
Anto
R version 2.9.2
example dataset:
ExponValues
[1] 2018.34 2012.54 2018.85 2023.52 2054.58 2132.61 2247.17 2468.32 2778.47
ExponCycles
[1] 17 18 19 20 21 22 23 24 25
Example starting estimate calculation
Y0 <- ExponValues[1]
E <-
weighted.mean((ExponValues-eY0)[-1][-1]/(ExponValues-eY0)[-1][-(length(ExponValues)-1)],(1-abs(seq(-1,1,length=(length(ExponValues)-2)))^3)^3)
alpha <-
weighted.mean((ExponValues[-1]...