Estimation and comparison of flowering curves I am a research scholar and monitoring phenological events of timber line at Himalayan region from past 4 years. During data analysis I found a research paper Estimation and comparison of flowering curve similar to my work. 
In this paper bbmle package was used and five parameters ($β_0, ... β_4$) describe: (i) the height; (ii) the peak date; (iii) the range; (iv) the symmetry; and (v) the peakedness of the regression curve was calculated. I also read the appendix table and followed the code to estimate these parameter but as a newbie I failed to calculate.
Appendix
library(bbmle) ## depends R(≥ 2.0.0)
## Collect data together as a data frame,
fdat <- data.frame(Days=c(212:238,250:271),
Count=c(0,2,2,6,10,18,29,39,59,75,104,130,
145,169,193,209,216,227,231,214,212,226,242,
225,214,202,211,104,90,70,55,52,45,38,29,22,
14,15,14,13,11,6,5,4,3,2,1,1,0))
## Define function
GESN <- function(x,b0,b1,b2,b3,b4) {
exp(b0-abs(((x-b1)/(b2∗(1+b3∗(sign(x-b1))))))ˆ(b4))
}
## Get reasonable starting values
startvals <- list(b0=log(250),b1=230,b2=15,b3=0,b4=2)

Please help me to find these parameters as they are mentioned in figure number 5 (link 1).
 A: You have not provided the full code, so I'll just go with the code you have provided. It seems to me that you have a simple syntax error in the second line because you copy&pasted from the paper. You have
GESN <- function(x,b0,b1,b2,b3,b4) { exp(b0-abs(((x-b1)/(b2∗(1+b3∗(sign(x-b1))))))ˆ(b4)) }

but you need (note the difference between circumflex  ˆ and caret ^)
GESN <- function(x,b0,b1,b2,b3,b4) { exp(b0-abs(((x-b1)/(b2∗(1+b3∗(sign(x-b1))))))^(b4)) }

Maybe give this a shot with the full code and report back if it does not work? In general, when copy&pasting from papers and similar sources, check every line very carefully to make sure that all special characters are correct.
A: The full appendix table is here:

I am also posting the startvals for the year 2007 as mention in appendix. look the values in figure below for year 2007..

the main problem is how to calculate startvals for example data of year 2007 as shown in figure where (β0, ... β4) describe: (i) the height; (ii) the peak date; (iii) the range;
(iv) the symmetry; and (v) the peakedness of the regression curve.
Please help
