`sortedXyData`

ObjectThis 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.

`sortedXyData(x, y, data)`

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

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.

`selfStart`

, `NLSstClosestX`

,
`NLSstLfAsymptote`

, `NLSstRtAsymptote`

# NOT RUN { DNase.2 <- DNase[ DNase$Run == "2", ] sortedXyData( expression(log(conc)), expression(density), DNase.2 ) # }