all.equal
Test if Two Objects are (Nearly) Equal
all.equal(x, y) is a utility to compare R objects x
and y testing ‘near equality’. If they are different,
comparison is still made to some extent, and a report of the
differences is returned. Don't use all.equal directly in
if expressions---either use isTRUE(all.equal(....)) or
identical if appropriate.
- Keywords
- utilities, arith, programming, logic
Usage
all.equal(target, current, ...)
"all.equal"(target, current, tolerance = .Machine$double.eps ^ 0.5, scale = NULL, check.attributes = TRUE, ...)
attr.all.equal(target, current, check.attributes = TRUE, check.names = TRUE, ...)Arguments
- target
- R object.
- current
- other R object, to be compared with
target. - ...
- Further arguments for different methods, notably the following two, for numerical comparison:
- tolerance
- numeric $\ge$ 0. Differences smaller than
toleranceare not considered. - scale
- numeric scalar > 0 (or
NULL). See ‘Details’. - check.attributes
- logical indicating if the
attributesoftargetandcurrent(other than the names) should be compared. - check.names
- logical indicating if the
names(.)oftargetandcurrentshould be compared.
Details
all.equal is a generic function, dispatching methods on the
target argument. To see the available methods, use
methods("all.equal"), but note that the default method
also does some dispatching, e.g. using the raw method for logical
targets.
Numerical comparisons for scale = NULL (the default) are done
by first computing the mean absolute difference of the two numerical
vectors. If this is smaller than tolerance or not finite,
absolute differences are used, otherwise relative differences scaled
by the mean absolute difference.
If scale is positive, absolute comparisons are made after
scaling (dividing) by scale.
For complex target, the modulus (Mod) of the
difference is used: all.equal.numeric is called so arguments
tolerance and scale are available.
The method for the date-time class "POSIXct" by default
allows a tolerance of tolerance = 0.001 seconds.
attr.all.equal is used for comparing
attributes, returning NULL or a
character vector.
Value
-
Either
TRUE (NULL for attr.all.equal) or a vector
of mode "character" describing the differences
between target and current.
Warning
Arguments other than target and current should be
specified via their full name: this will be required as from R 3.1.0.
References
Chambers, J. M. (1998)
Programming with Data. A Guide to the S Language.
Springer (for =).
See Also
Examples
library(base)
all.equal(pi, 355/113)
# not precise enough (default tol) > relative error
d45 <- pi*(1/4 + 1:10)
stopifnot(
all.equal(tan(d45), rep(1, 10))) # TRUE, but
all (tan(d45) == rep(1, 10)) # FALSE, since not exactly
all.equal(tan(d45), rep(1, 10), tolerance = 0) # to see difference