Signum
From Encyclopedia of Mathematics
The function of a real variable 
which is equal to 1 if 
is positive, equal to 0 if 
is zero and equal to 
if 
is negative. Notation: 
or 
. Thus,
 |
Comments
The signum function is usually extended to the complex plane by 
if 
(and 
). Thus, it measures the angle of the ray from the origin on which 
lies.
How to Cite This Entry:
Signum. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Signum&oldid=28818
Signum. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Signum&oldid=28818
This article was adapted from an original article by Yu.A. Gor'kov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article