# isapprox

isapprox(x, y; rtol::Real=sqrt(eps), atol::Real=0)

Inexact equality comparison: `true`

if `norm(x-y) <= atol + rtol*max(norm(x), norm(y))`

. The default `atol`

is zero and the default `rtol`

depends on the types of `x`

and `y`

.

For real or complex floating-point values, `rtol`

defaults to `sqrt(eps(typeof(real(x-y))))`

. This corresponds to requiring equality of about half of the significand digits. For other types, `rtol`

defaults to zero.

`x`

and `y`

may also be arrays of numbers, in which case `norm`

defaults to `vecnorm`

but may be changed by passing a `norm::Function`

keyword argument. (For numbers, `norm`

is the same thing as `abs`

.)

The binary operator `≈`

is equivalent to `isapprox`

with the default arguments, and `x ≉ y`

is equivalent to `!isapprox(x,y)`

.

## Examples

## See Also

cmp, float, get_bigfloat_precision, get_rounding, get_zero_subnormals, isapprox, maxintfloat, mod2pi, nextfloat, precision, prevfloat, rationalize, round, set_bigfloat_precision, set_rounding, set_zero_subnormals, significand, with_bigfloat_precision, with_rounding,## User Contributed Notes

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