Comparison {base} | R Documentation |
Binary operators which allow the comparison of values in vectors.
x < y x > y x <= y x >= y x == y x != y
Comparison of strings in character vectors is lexicographic within the
strings using the collating sequence of the locale in use: see
locales
. The collating sequence of locales such as
en_US
is normally different from C
(which should use
ASCII) and can be surprising.
A vector of logicals indicating the result of the element by element
comparison. The elements of shorter vectors are recycled as
necessary.
Objects such as arrays or time-series can be compared this way
provided they are conformable.
Don't use ==
and !=
for tests, such as in if
expressions, where you must get a single TRUE
or
FALSE
. Unless you are absolutely sure that nothing unusual
can happen, you should use the identical
function
instead.
For numerical values, remember ==
and !=
do not allow
for the finite representation of fractions, nor for rounding error.
Using all.equal
with identical
is almost
always preferable. See the examples.
Syntax
for operator precedence.
x <- rnorm(20) x < 1 x[x > 0] x1 <- 0.5 - 0.3 x2 <- 0.3 - 0.1 x1 == x2 # FALSE on most machines identical(all.equal(x1, x2), TRUE) # TRUE everywhere