nextpow2 - Next higher power of 2

Syntax

Description

p = nextpow2(A) returns the smallest power of two that is greater than or equal to the absolute value of A. (That is, p that satisfies 2^p >= abs(A)).

This function is useful for optimizing FFT operations, which are most efficient when sequence length is an exact power of two.

Examples

For any integer n in the range from 513 to 1024, nextpow2(n) is 10.

For vector input, nextpow2(n) returns an element-by-element result:

A = [1 2 3 4 5 9 519]
nextpow2(A)
ans =

     0     1     2     2     3     4    10

See Also

fft | log2 | pow2

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