NAME¶
matho-primes - generate consecutive prime numbers
SYNOPSIS¶
matho-primes [start [stop]] ["twin"] ["pal" [base]]
matho-primes [-htu] [-c count] [-m number] [-p base] [start [stop]]
DESCRIPTION¶
This command-line utility is optionally part of the
mathomatic(1)
package. It quickly computes any number of consecutive prime numbers using a
windowing, memory efficient sieve of Eratosthenes algorithm, dumping them to
standard output. They are displayed one prime per line in ascending order,
unless the "twin" option is specified, which displays only twin
primes, two primes per line.
Generates up to 18 decimal digit primes, or whatever is the number of digits of
precision for a floating point
long double in the C compiler used to
compile this utility. Note that this utility might be compiled to use only
double precision floating point, if long double precision is not fully
supported by the C compiler or hardware, allowing at most 15 decimal digit
primes in that case.
Ways to verify that this utility is working are to pipe the output into the Unix
"factor" utility, or compare the output with the BSD Games
"primes" utility.
All numbers displayed by this utility are decimal (base 10) prime numbers. A
prime number is an integer that cannot be factored.
A range may be specified on the command line, otherwise the starting number and
the number of primes to output is prompted for. The range is
start to
stop inclusive, and
stop must be greater than or equal to
start.
If the
-c option is specified, the number of lines of primes displayed is
limited to the decimal count that follows this option.
If the
-t or "twin" option is specified on the command line,
only
twin primes will be displayed. Twin primes are two primes that
differ in value by 2. Each twin pair is displayed together on the same line
separated by a space character.
If the
-p or "pal" option is specified on the command line,
only
palindromic primes are displayed. Palindromes are symmetrical,
they read exactly the same forward and backward. The palindromic number
base may be specified, the default is base 10. The
base can be
any integer greater than 1. Primes are always displayed in decimal (base 10).
The version number and short help on the allowed command-line parameters and
usage information are displayed when given the
-h option.
With the
-u option, all output (standard output and standard error
output) is set to be unbuffered, making all output happen immediately, instead
of when the output buffer is full or when the program terminates or waits for
input.
The
-m option changes the memory size of the prime number sieve window.
It is followed by a decimal, floating point number which is a multiplier of
the default window size. It is possible that changing the memory size may
speed up the total run time; otherwise there is no reason to use this option.
AUTHOR¶
George Gesslein II (gesslein@mathomatic.org) at
"
http://www.mathomatic.org".
REPORTING BUGS¶
If you find a bug, please report it to the author or at
"
https://launchpad.net/mathomatic".
SEE ALSO¶
mathomatic(1),
primorial(1),
matho-mult(1),
matho-sum(1)