# 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. Do not 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, …)`# S3 method for numeric
all.equal(target, current,
tolerance = sqrt(.Machine$double.eps), scale = NULL,
…, check.attributes = TRUE)

# S3 method for list
all.equal(target, current, …,
check.attributes = TRUE, use.names = TRUE)

# S3 method for environment
all.equal(target, current, all.names=TRUE, …)

# S3 method for POSIXt
all.equal(target, current, …, tolerance = 1e-3, scale)

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

`tolerance`

are not reported. The default value is close to`1.5e-8`

.- scale
numeric scalar > 0 (or

`NULL`

). See ‘Details’.- check.attributes
logical indicating if the

`attributes`

of`target`

and`current`

(other than the names) should be compared.- use.names
logical indicating if

`list`

comparison should report differing components by name (if matching) instead of integer index. Note that this comes after`…`

and so must be specified by its full name.- all.names
logical passed to

`ls`

indicating if “hidden” objects should also be considered in the environments.- check.names
logical indicating if the

`names(.)`

of`target`

and`current`

should 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.

Remember that arguments which follow `…`

must be specified by
(unabbreviated) name. It is inadvisable to pass unnamed arguments in
`…`

as these will match different arguments in different
methods.

Numerical comparisons for `scale = NULL`

(the default) are
typically on *relative difference* scale unless the target values
are close to zero: First, the mean absolute difference of the two
numerical vectors is computed. If this is smaller than
`tolerance`

or not finite, absolute differences are used,
otherwise relative differences scaled by the mean absolute
`target`

value.
(Note that these comparisons are computed only for those vector elements
where `target`

is not `NA`

and differs from `current`

.)

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 `list`

method compares components of
`target`

and `current`

recursively, passing all other
arguments, as long as both are “list-like”, i.e., fulfill
either `is.vector`

or `is.list`

.

The `environment`

method works via the `list`

method,
and is also used for reference classes (unless a specific
`all.equal`

method is defined).

The methods for the date-time classes by default allow a tolerance of
`tolerance = 0.001`

seconds, and ignore `scale`

.

`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`

.

##### References

Chambers, J. M. (1998)
*Programming with Data. A Guide to the S Language*.
Springer (for `=`

).

##### See Also

##### Examples

`library(base)`

```
# NOT RUN {
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
## advanced: equality of environments
ae <- all.equal(as.environment("package:stats"),
asNamespace("stats"))
stopifnot(is.character(ae), length(ae) > 10,
## were incorrectly "considered equal" in R <= 3.1.1
all.equal(asNamespace("stats"), asNamespace("stats")))
# }
```

*Documentation reproduced from package base, version 3.5.1, License: Part of R 3.5.1*