signum

(signum number)

Returns -1, 0, or 1 indicating the sign of number, preserving its numeric type. An integer or ratio argument yields an integer result, while a float argument yields a float result (e.g. 1.0, 0.0, -1.0). A complex argument yields its unit vector z/|z| in floats -- #C(0.6 0.8) for #c(3 4) -- while a zero answers the canonicalization of its own parts (0 for exact parts, #C(0.0 0.0) for float parts).