signifz {UNF} | R Documentation |
Rounds the value to a specified number of significant digits, using IEEE 754 rounding towards zero rounding mode
signifz (x, digits=6)
x |
A numeric vector. |
digits |
integer indicating the precision to be used |
`signifz' rounds the values in its first argument to the specified number of significant digits, using IEC 60559/IEEE 754 ``round towards zero'' mode.
Rounding toward zero assures that signifz(signifz(x,digits=m),digits=n)
=
signifz(x,digits=n)
for $m>n$, an important property for creating approximate
fingerprints. It can, however, produce more rounding error than rounding toward nearest.
The maximum log relative error (LRE) for the former is (digits-1) while the
maximum LRE for the latter is `digits'. Hence, you may wish to use one more
significant digit with signifz
than with signif
.
Micah Altman Micah_Altman@harvard.edu
http://thedata.org/index.php/Main/UNF
signif
, unf
# note the difference signif(pi,digits=5) signifz(pi,digits=5)