Create a sortedXyData object
Usage
sortedXyData(x, y, data)
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
|
Description
This is 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.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.Author(s)
Jose Pinheiro and Douglas BatesSee Also
selfStart
, NLSstClosestX
,
NLSstLfAsymptote
, NLSstRtAsymptote
Examples
library( lme )
data( DNase )
DNase.2 <- DNase[ DNase$Run == "2", ]
sortedXyData( expression(log(conc)), expression(density), DNase.2 )