Base 2 logarithm and dissect floating-point numbers into exponent and mantissa Syntax
Y = log2(X) [F,E] = log2(X)
Y = log2(X) computes the base 2 logarithm of the elements of X.
[F,E] = log2(X) returns arrays F and E. Argument F is an array of real values, usually in the range 0.5 <= abs(F) < 1. For real X, F satisfies the equation: X = F.*2.^E. Argument E is an array of integers that, for real X, satisfy the equation: X = F.*2.^E.
For IEEE arithmetic, the statement [F,E] = log2(X) yields the values:
1 1/2 1 pi pi/4 2 -3 -3/4 2 eps 1/2 -51 realmax 1-eps/2 1024 realmin 1/2 -1021 More About
expand all Tips This function corresponds to the ANSI C function frexp() and the IEEE floating-point standard function logb(). Any zeros in X produce F = 0 and E = 0.