The %d==%, %d!=% %d<%, %d>%, %d<=%, %d>=%
(in)equality operators
perform decimal (type "double") number truth testing.
They are virtually equivalent to the regular (in)equality operators, ==, !=, <, >, <=, >=
,
except for 2 aspects:
The decimal number (in)equality operators assume that if the absolute difference between any 2 numbers
x
andy
is smaller than the Machine tolerance,sqrt(.Machine$double.eps)
, thenx
andy
should be consider to be equal.
For example:(0.1 * 7) == 0.7
returnsFALSE
, even though they are equal, due to the way decimal numbers are stored in programming languages like 'R' and 'Python'.
But(0.1 * 7) %d==% 0.7
returnsTRUE
.Only numeric input is allowed, so characters are not coerced to numbers.
I.e.1 < "a"
givesTRUE
, whereas1 %d<% "a"
gives an error.
For character equality testing, see %s==% from the 'stringi' package.
Thus these operators provide safer decimal number (in)equality tests.
There are also the x %d{}% bnd
and x %d!{}% bnd
operators,
where bnd
is a vector of length 2,
or a 2-column matrix (nrow(bnd)==length(x)
or nrow(bnd)==1
).
The x %d{}% bnd
operator checks if x
is within the closed interval with bounds defined by bnd
.
The x %d!{}% bnd
operator checks if x
is outside the closed interval with bounds defined by bnd
.
Moreover, the function is_wholenumber()
is added, to safely test for whole numbers.
Usage
x %d==% y
x %d!=% y
x %d<% y
x %d>% y
x %d<=% y
x %d>=% y
x %d{}% bnd
x %d!{}% bnd
is_wholenumber(x, tol = sqrt(.Machine$double.eps))
Arguments
- x, y
numeric vectors, matrices, or arrays.
- bnd
either a vector of length 2, or a matrix with 2 columns and 1 row, or else a matrix with 2 columns where
nrow(bnd)==length(x)
(or can be recycled to benrow(bnd)==length(x)
).
The first element/column ofbnd
gives the lower bound of the closed interval;
The second element/column ofbnd
gives the upper bound of the closed interval.- tol
a single, strictly positive number close to zero, giving the tolerance.
Value
For the %d...%
operators:
A logical vector with the same dimensions as x
,
indicating the result of the element by element comparison.
NOTE: Inf
by Inf
and -Inf
by -Inf
comparisons with
the %d...%
operators return NA
.
For is_wholenumber()
:
A logical vector with the same dimensions as x
,
indicating the result of the element by element comparison.
NOTE: Inf
, -Inf
, NaN
and NA
all return NA
for is_wholenumber()
.
Details
The operators described in this page are defined in terms of the existing base
Logic operators,
and should therefore be compatible with (S3) classes
that have method dispatches defined for relational operators.
Examples
x <- c(0.3, 0.6, 0.7)
y <- c(0.1 * 3, 0.1 * 6, 0.1 * 7)
print(x)
#> [1] 0.3 0.6 0.7
print(y)
#> [1] 0.3 0.6 0.7
x == y # gives FALSE, but should be TRUE
#> [1] FALSE FALSE FALSE
x != y # gives TRUE, should be FALSE
#> [1] TRUE TRUE TRUE
x > y # not wrong
#> [1] FALSE FALSE FALSE
x < y # gives TRUE, should be FALSE
#> [1] TRUE TRUE TRUE
# same as above, but here the results are correct:
x %d==% y # correct
#> [1] TRUE TRUE TRUE
x %d!=% y # correct
#> [1] FALSE FALSE FALSE
x %d<% y # correct
#> [1] FALSE FALSE FALSE
x %d>% y # correct
#> [1] FALSE FALSE FALSE
x %d<=% y # correct
#> [1] TRUE TRUE TRUE
x %d>=% y # correct
#> [1] TRUE TRUE TRUE
# check if numbers are in closed interval:
x <- c(0.3, 0.6, 0.7)
bnd <- cbind(x - 0.1, x + 0.1)
x %d{}% bnd
#> [1] TRUE TRUE TRUE
x %d!{}% bnd
#> [1] FALSE FALSE FALSE
# These operators work for integers also:
x <- 1L:5L
y <- 1L:5L
x %d==% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x %d!=% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d<% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d>% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d<=% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x %d>=% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x <- 1L:5L
y <- x + 1L
x %d==% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d!=% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x %d<% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x %d>% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d<=% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x %d>=% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x <- 1L:5L
y <- x - 1L
x %d==% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d!=% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x %d<% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d>% y
#> [1] TRUE TRUE TRUE TRUE TRUE
x %d<=% y
#> [1] FALSE FALSE FALSE FALSE FALSE
x %d>=% y
#> [1] TRUE TRUE TRUE TRUE TRUE
# is_wholenumber:
is_wholenumber(1:10 + c(0, 0.1))
#> [1] TRUE FALSE TRUE FALSE TRUE FALSE TRUE FALSE TRUE FALSE