epsis a permanent variable whose value is initially the distance from 1.0 to the next largest floating-point number. It can be assigned any value, including 0.
epsis a default tolerance for
rank, as well as several other MATLAB functions, so changing the value of
epschanges the way some functions operate. On machines with IEEE floating-point arithmetic,
eps = 2^(-52), which is roughly 2.22e-16.
(c) Copyright 1994 by The MathWorks, Inc.