Running examples in 'phenology-Ex.R' failed
The error most likely occurred in:

> ### Name: map_phenology
> ### Title: Generate a likelihood map varying Phi and Delta.
> ### Aliases: map_phenology
> 
> ### ** Examples
> 
> library("phenology")
> # Read a file with data
> data(Gratiot)
> # Generate a formatted list nammed data_Gratiot 
> data_Gratiot <- add_phenology(Gratiot, name = "Complete", 
+ 		reference = as.Date("2001-01-01"), format = "%d/%m/%Y")
The columns with rookery name does not exist; I create one
Site: Complete
Reference date: 2001-01-01
> # Generate initial points for the optimisation
> parg <- par_init(data_Gratiot, fixed.parameters = NULL)
> # Run the optimisation
> ## Not run: 
> ##D result_Gratiot <- fit_phenology(data = data_Gratiot, 
> ##D 		fitted.parameters = parg, fixed.parameters = NULL)
> ## End(Not run)
> data(result_Gratiot)
> # Extract the fitted parameters
> parg1 <- extract_result(result_Gratiot)
> # Add constant Alpha and Tau values 
> # [day d amplitude=(Alpha+Nd*Beta)^Tau with Nd being the number of counts for day d]
> pfixed <- c(parg1, Alpha=0, Tau=1)
> pfixed <- pfixed[-which(names(pfixed)=="Theta")]
> # The only fitted parameter will be Beta
> parg2 <- c(Beta=0.5, parg1["Theta"])
> # Generate a likelihood map 
> # [default Phi=seq(from=0.1, to=20, length.out=100) but it is very long]
> # Take care, it takes 20 hours ! The data map_Gratiot has the result
> ## Not run: 
> ##D library(phenology)
> ##D map_Gratiot <- map_phenology(data = data_Gratiot, 
> ##D                              Phi = seq(from=0.1, to=30, length.out=100), 
> ##D 		                          fitted.parameters = parg2, 
> ##D 		                          fixed.parameters = pfixed)
> ## End(Not run)
> data(map_Gratiot)
> # Plot the map
> plot(map_Gratiot, col = heat.colors(128))
Error in plot.phenologymap(map_Gratiot, col = heat.colors(128)) : 
  fields package is required for this function; Please install it first
Calls: plot -> plot.phenologymap
Execution halted