Topic: Utilities
Topic Description:
Basic R utilities used in many packages and functions, such as date and string manipulations, statistical distributions, geometry of lines and distances. The R package date is required for the two data functions.
File: utilities/distributions.r
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Function: logistic.standard
Function Description: logistic.standard
This is standard logistic function, but with asymptote and basement allowed. The latter are only implemented if extra parameters are passed. Moved from calc.surviv.r on 25 July 2010 to provide the standard logistic.Function Arguments:
| Argument | Default Value |
|---|---|
| x | |
| param | |
| log | FALSE |
| ... |
Function Source:
logistic.standard=function(x,param,log=FALSE,...)
{
x=as.matrix(x)
nopredictor=dim(x)[2]
a=param[1]
b=param[2:(nopredictor+1)]
asymp=IfElse(length(param)>nopredictor+1,param[nopredictor+2],1)
basement=IfElse(length(param)>nopredictor+2,param[nopredictor+3],0)
X=x%*%b
pwr=a+X
y=invlogit(pwr)
prob=y*(asymp-basement)+basement
infinite.pos=which(is.infinite(exp(pwr)))
prob[infinite.pos]=basement+asymp
if(log) return(log(prob))
return(prob)
}
{
x=as.matrix(x)
nopredictor=dim(x)[2]
a=param[1]
b=param[2:(nopredictor+1)]
asymp=IfElse(length(param)>nopredictor+1,param[nopredictor+2],1)
basement=IfElse(length(param)>nopredictor+2,param[nopredictor+3],0)
X=x%*%b
pwr=a+X
y=invlogit(pwr)
prob=y*(asymp-basement)+basement
infinite.pos=which(is.infinite(exp(pwr)))
prob[infinite.pos]=basement+asymp
if(log) return(log(prob))
return(prob)
}