Horizontal Asymptote on the Left Side

DESCRIPTION:

Provide an initial guess at the horizontal asymptote on the left side (i.e. small values of x) of the graph of y versus x from the xy object. Primarily used within initial functions for self-starting nonlinear regression models.

USAGE:

NLSstLfAsymptote(xy) 

REQUIRED ARGUMENTS:

xy
a sortedXyData object

VALUE:

A single numeric value estimating the horizontal asymptote for small x .

EXAMPLES:

DNase.2 <- DNase[ DNase$Run == "2", ] 
DN.srt <- sortedXyData( expression(log(conc)), expression(density), DNase.2 ) 
NLSstLfAsymptote( DN.srt )