ffconform: Get most conforming argument

In ff: Memory-Efficient Storage of Large Data on Disk and Fast Access Functions

Get most conforming argument

Description

ffconform returns position of 'most' conformable ff argument or zero if the arguments are not conforming

Usage

ffconform(..., vmode = NULL, fail = "stop")

Arguments

...	two or more ff objects
vmode	handing over target vmode here supresses searching for a common vmode, see maxffmode
fail	the name of a function to call if not-conforming, default stop

Details

A reference argument is defined to be the first argument with a dim attribute or the longest vector. The other arguements are then compared to the reference to check for conformity, which is violated if vmodes are not conforming or if the reference has not a multiple length of each other or if the dimensions do not match or if we have a dimorder conflict because not all arguments have the same dimorderStandard.

Value

the position of the most conforming argument or 0 (zero) if not conforming.

Note

xx Work in progress for package R.ff

Author(s)

Jens Oehlschlägel

See Also

ffsuitable, maxffmode, ymismatch, stop, warning, dimorderStandard

Examples

  a <- ff(1:10)
  b <- clone(a)
  c <- ff(1:20)
  d <- ff(1:21)
  ffconform(a,b)
  ffconform(c,a)
  ffconform(a,c)
  ffconform(c,a,b)

  d1 <- ff(1:20, dim=c(2,10))
  d2 <- ff(1:20, dim=c(10,2))
  ffconform(c,d1)
  ffconform(c,d2)
  ffconform(d1,c)
  ffconform(d2,c)
  try(ffconform(d1,d2))
  ffconform(d1,d1)

  rm(a,b,c,d1,d2); gc()

ff documentation built on Feb. 16, 2023, 7:48 p.m.