A multifractal is a set or measure whose local scaling behavior requires a spectrum of exponents rather than a single
fractal dimension. For a measure , the local exponent
is defined by
when the limit exists, where is the ball of radius
centered at
and
for all sufficiently small
. This expresses power-law scaling without requiring
to tend to 1. The multifractal spectrum
is the Hausdorff
dimension of the set of points having exponent
. A monofractal is the special case in which one exponent
suffices.