Create a sortedXyData object

DESCRIPTION:

This is a constructor function for the class of sortedXyData objects. These objects are mostly used in the initial function for a self-starting nonlinear regression model, which will be of the selfStart class.

USAGE:

sortedXyData(x, y, data) 

REQUIRED ARGUMENTS:

x
a numeric vector or an expression that will evaluate in data to a numeric vector
y
a numeric vector or an expression that will evaluate in data to a numeric vector
data
an optional data frame in which to evaluate expressions for x and y, if they are given as expressions

VALUE:

A sortedXyData object. This is a data frame with exactly two numeric columns, named x and y. The rows are sorted so the x column is in increasing order. Duplicate x values are eliminated by averaging the corresponding y values.

SEE ALSO:

, , ,

EXAMPLES:

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