Comparison {base} | R Documentation

## Relational Operators

### Description

Binary operators which allow the comparison of values in atomic vectors.

### Usage

    x < y
    x > y
    x <= y
    x >= y
    x == y
    x != y

### Arguments

`x, y` | atomic vectors, or other objects for which methods have been written.

### Details

The binary comparison operators are generic functions: methods can be written for them individually or via the `Ops`) group generic function.

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.

### Value

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.

### Note

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.

### References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

### See Also

`Syntax` for operator precedence.

### Examples

    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

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