R/get.weight.function.R

In curvetest: The package will formally test two curves represented by discrete data sets to be statistically equal or not when the errors of the two curves were assumed either equal or not using the tube formula to calculate the tail probabilities.

get.weight.function <-
function(type){ #To get the weight function from the chracter string specified in type. 
  if(is.character(type)) { 
  if(!type%in%c("Trio","Gaussian", "Uniform", "Triweight", "Triangle", "Epanechnikov", "Quartic"))
      stop("type  not in known types.\n")
  f<-switch(EXPR=type, 
        "Trio"=  function(x)        (1 - abs(x)^3)^3 * (abs(x) < 1),       
        "Gaussian" =function(x)     exp(-x^2/2)/sqrt(2 * pi), 
        "Uniform"=function(x)       (abs(x) <= 1)/2,
        "Triweight"=  function(x)   (1 - x^2)^3 * 35/32 * (abs(x) <= 1), 
        "Triangle"= function(x)     (1 - abs(x))*(abs(x) <= 1),   
        "Epanechnikov"= function(x) (1 - x^2) * 3/4 * (abs(x) <= 1),
        "Quartic"=function(x)       (1 - x^2)^2 * 15/16 * (abs(x) <= 1)) 
  attr(f,"name")=type 
  return(f)
  }else if(is.function(type)) return(type)  else stop("Wrong type specified.")
}