pow2

Power of two, or a number scaled by a power of two.

Category: Mathematics > Elementary Math

Syntax

Y = pow2(X)

Y = pow2(F, E)

Description

Multiplying by a power of two only changes the exponent of a floating-point number, so pow2(F, E) is exact: no rounding error is introduced. This is why it is used to rebuild a number from a mantissa and exponent. Fractional exponents work as well: pow2(0.5) is sqrt(2).

Input arguments

X

Exponent array.

F, E

Mantissa and exponent arrays of compatible sizes.

Output arguments

Y

Array with the size given by implicit expansion of the inputs.

Example

One and two arguments

pow2(3)
pow2([1 2 3], 2)
pow2(-1)

ans = 8
ans = 1×3

     4     8    12
ans = 0.5000

See also

log2 nextpow2 power exp