www.gusucode.com > elfun工具箱matlab源码程序 > elfun/log2.m
%LOG2 Base 2 logarithm and dissect floating point number. % Y = LOG2(X) is the base 2 logarithm of the elements of X. % % [F,E] = LOG2(X) for each element of the real array X, returns an % array F of real numbers, usually in the range 0.5 <= abs(F) < 1, % and an array E of integers, so that X = F .* 2.^E. Any zeros in X % produce F = 0 and E = 0. This corresponds to the ANSI C function % frexp() and the IEEE floating point standard function logb(). % % See also LOG, LOG10, POW2, NEXTPOW2, REALMAX, REALMIN. % Copyright 1984-2005 The MathWorks, Inc. % Built-in function.