NAME
    places - return number of "decimal" places in a fractional part

SYNOPSIS
    places(x [,b])

TYPES
    x		real
    b		integer >= 2, defaults to 10

    return	integer

DESCRIPTION
    Returns the least non-negative integer n for which  b^n * x  is an
    integer, or -1 if there is no such integer.

    places(x,b) = 0 if and only if x is an integer.

    If omitted, b is assumed to be 10.  If given, b must be an
    integer > 1.

    places(x,b) = n > 0 if and only if the fractional part of abs(x)
    has a finite base-b "decimal" representation with n digits of which
    the last digit is nonzero.  This occurs if and only if every prime
    factor of den(x) is a factor of b.

EXAMPLE
    > print places(3), places(0.0123), places(3.70), places(1e-10), places(3/7)
    0 4 1 10 -1

    > print places(0.0123, 2), places(.625, 2), places(.625, 8)
    -1 3 1

LIMITS
    b > 1

LINK LIBRARY
    long qplaces(NUMBER *q, ZVALUE base)

SEE ALSO
    digit, digits