as.xts.ts: no visible global function definition for 'as.yearqtr'
as.xts.ts: no visible global function definition for 'as.yearmon'
rollapply.xts: no visible global function definition for 'na.fill'
NB: .First.lib is obsolete and will not be used in R >= 3.0.0
File 'yacca/R/zzz.R':
  .First.lib calls:
    cat(paste("'", ehelp[4], "'\n", "Version ", ehelp[2], " created on ",     ehelp[3], ".\n", sep = ""))
    cat(paste(substring(ehelp[3], first = 16), "\n", "Version ",     substring(ehelp[4], first = 16), " created on ", substring(ehelp[5],         first = 16), ".\n", sep = ""))
    cat("Copyright (c) 2008, Carter T. Butts, University of California-Irvine\n")
    cat("For citation information, type citation(\"yacca\").\n")
    cat("Type help(\"yacca-package\") to get started.\n")

Package startup functions should use 'packageStartupMessage' to
  generate messages.
See section 'Good practice' in '?.onAttach'.
tZC_NS: no visible global function definition for 'cmpfun'
tZC_NS_extra: no visible global function definition for 'cmpfun'
tZC_SV: no visible global function definition for 'cmpfun'
tZC_SV_extra: no visible global function definition for 'cmpfun'
epirice.weather: no visible binding for global variable
  'weather_SouthAsia'
maize.multisy: no visible binding for global variable
  'weather_EuropeEU'
maize.multisy240 : <anonymous>: no visible binding for global variable
  'weather_EuropeEU'
maize.weather: no visible binding for global variable
  'weather_FranceWest'
param.rtriangle: no visible global function definition for 'rtriangle'
population.age.model.ode: no visible global function definition for
  'ode'
population.age.model.ode: no visible global function definition for
  'rkMethod'
predator.prey.model: no visible global function definition for 'ode'
predator.prey.model: no visible global function definition for
  'rkMethod'
watbal.weather: no visible binding for global variable
  'weather_FranceWest'
Namespaces in Imports field not imported from:
  'dplyr' 'ggplot2' 'lubridate'
  All declared Imports should be used.