capture-n-write: Capture output and Write / Print First and Last Parts

In mmaechler/sfsmisc: Utilities from 'Seminar fuer Statistik' ETH Zurich

Capture output and Write / Print First and Last Parts

Description

Capture output and print first and last parts, eliding middle parts. Particularly useful for teaching purposes, and, e.g., in Sweave (RweaveLatex).

By default, when middle = NA, capture.output(EXPR, first, last) basically does

    co <- capture.output(EXPR)
    writeLines(head(co, first))
    cat( ... dotdots ...)
    writeLines(tail(co, last))
  

Usage

capture.and.write(EXPR, first, last = 2, middle = NA,
                  i.middle, dotdots = " ....... ", n.dots = 2)

Arguments

EXPR	the (literal) expression the output of which is to be captured.
first	integer: how many lines should be printed at beginning.
last	integer: how many lines should be printed at the end.
middle	numeric (or NA logical):
i.middle	index start of middle part
dotdots	string to be used for elided lines
n.dots	number of dotdots lines added between parts.

Value

return value of capture.output(EXPR).

Author(s)

Martin Maechler, ETH Zurich

See Also

head, tail

Examples

x <- seq(0, 10, by = .1)

## for matrix, dataframe, .. first lines include a header line:
capture.and.write( cbind(x, log1p(exp(x))),  first = 5)

## first, *middle* and last :
capture.and.write( cbind(x, x^2, x^3), first = 4, middle = 3, n.dots= 1)

mmaechler/sfsmisc documentation built on Feb. 28, 2024, 4:18 a.m.