R: Evaluate an Expression in Each Row of a Hyperframe

with.hyperframe {spatstat} | R Documentation

## Evaluate an Expression in Each Row of a Hyperframe

### Description

An expression, involving the names of columns in a hyperframe, is evaluated separately for each row of the hyperframe.

### Usage

    ## S3 method for class 'hyperframe'
    with(data, expr, ...,
                             simplify = TRUE,
                             ee = NULL, enclos=NULL)

### Arguments

`data` | A hyperframe (object of class `"hyperframe"`) containing data.
`expr` | An R language expression to be evaluated.
`...` | Ignored.
`simplify` | Logical. If `TRUE`, the return value will be simplified to a vector whenever possible.
`ee` | Alternative form of `expr`, as an object of class `"expression"`.
`enclos` | An environment in which to search for objects that are not found in the hyperframe. Defaults to `parent.frame()`.

### Details

This function evaluates the expression `expr` in each row of the hyperframe `data`. It is a method for the generic function `with`.

The argument `expr` should be an R language expression in which each variable name is either the name of a column in the hyperframe `data`, or the name of an object in the parent frame (the environment in which `with` was called.) The argument `ee` can be used as an alternative to `expr` and should be an expression object (of class `"expression"`).

For each row of `data`, the expression will be evaluated so that variables which are column names of `data` are interpreted as the entries for those columns in the current row.

For example, if a hyperframe `h` has columns called `A` and `B`, then `with(h, A != B)` inspects each row of `data` in turn, tests whether the entries in columns `A` and `B` are equal, and returns the n logical values.

### Value

Normally a list of length n (where n is the number of rows) containing the results of evaluating the expression for each row. If `simplify=TRUE` and each result is a single atomic value, then the result is a vector or factor containing the same values.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

and Rolf Turner r.turner@auckland.ac.nz

### See Also

`hyperframe`, `plot.hyperframe`

### Examples

      # generate Poisson point patterns with intensities 10 to 100
       H <- hyperframe(L=seq(10,100, by=10))
       X <- with(H, rpoispp(L))

[Package spatstat version 1.54-0 Index]