mirror of
https://github.com/lcn2/calc.git
synced 2025-08-16 01:03:29 +03:00
66 lines
1.8 KiB
Plaintext
66 lines
1.8 KiB
Plaintext
NAME
|
|
prevprime - nearest prime less than specified number
|
|
|
|
SYNOPSIS
|
|
prevprime(n [,err])
|
|
|
|
TYPES
|
|
n real
|
|
err integer
|
|
|
|
return positive integer or err
|
|
|
|
DESCRIPTION
|
|
If n is an integer and 2 < n < 2^32, prevprime(n) returns the
|
|
nearest prime less than n.
|
|
|
|
If n <= 2 or >= 2^32 or n is fractional, prevprime(n, err)
|
|
returns the value of err.
|
|
|
|
Other cases cause a runtime error.
|
|
|
|
EXAMPLE
|
|
> print prevprime(10), prevprime(100), prevprime(1e6)
|
|
7 97 999983
|
|
|
|
> print prevprime(2,-99), prevprime(2^32,-99)
|
|
-99 -99
|
|
|
|
> print prevprime(2)
|
|
pprime arg 1 is <= 2
|
|
|
|
LIMITS
|
|
2 < n < 2^32
|
|
|
|
LINK LIBRARY
|
|
FULL zpprime(ZVALUE z)
|
|
|
|
SEE ALSO
|
|
nextprime
|
|
|
|
## Copyright (C) 1999 Landon Curt Noll
|
|
##
|
|
## Calc is open software; you can redistribute it and/or modify it under
|
|
## the terms of the version 2.1 of the GNU Lesser General Public License
|
|
## as published by the Free Software Foundation.
|
|
##
|
|
## Calc is distributed in the hope that it will be useful, but WITHOUT
|
|
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
|
|
## Public License for more details.
|
|
##
|
|
## A copy of version 2.1 of the GNU Lesser General Public License is
|
|
## distributed with calc under the filename COPYING-LGPL. You should have
|
|
## received a copy with calc; if not, write to Free Software Foundation, Inc.
|
|
## 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
|
|
##
|
|
## @(#) $Revision: 29.2 $
|
|
## @(#) $Id: prevprime,v 29.2 2000/06/07 14:02:33 chongo Exp $
|
|
## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/prevprime,v $
|
|
##
|
|
## Under source code control: 1995/12/18 12:34:58
|
|
## File existed as early as: 1995
|
|
##
|
|
## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
|
|
## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
|