FMS 2025.01-dev
Flexible Modeling System
|
Fortran-95 implementation of the Mersenne Twister 19937 algorithm. More...
Data Types | |
interface | new_randomnumbersequence |
type | randomnumbersequence |
The type containing the state variable. More... | |
Functions/Subroutines | |
subroutine, public | finalize_randomnumbersequence (twister) |
integer function, public | getrandomint (twister) |
Generate a random integer on the interval [0,0xffffffff]. | |
integer function, public | getrandompositiveint (twister) |
Generate a random integer on the interval [0,0x7fffffff] or [0,2**31]. Equivalent to genrand_int31 in the C code. | |
real(r8_kind) function, public | getrandomreal (twister) |
Generate a random number on [0,1] Equivalent to genrand_real1 in the C code. The result is stored as double precision but has 32 bit resolution. | |
type(randomnumbersequence) function | initialize_scalar (seed) |
type(randomnumbersequence) function | initialize_vector (seed) |
integer function | mixbits (u, v) |
subroutine | nextstate (twister) |
elemental integer function | temper (y) |
integer function | twist (u, v) |
Variables | |
integer, parameter | lmask = 2147483647 |
least significant r bits (0x7fffffffUL) | |
integer, parameter | m = 397 |
integer, parameter | matrix_a = -1727483681 |
constant vector a (0x9908b0dfUL) | |
integer, parameter | tmaskb = -1658038656 |
(0x9d2c5680UL) | |
integer, parameter | tmaskc = -272236544 |
(0xefc60000UL) | |
integer, parameter | umask = -2147483648_i8_kind |
most significant w-r bits (0x80000000UL) | |
Fortran-95 implementation of the Mersenne Twister 19937 algorithm.
Users must declare one or more variables of type randomNumberSequence in the calling procedure which are then initialized using a required seed. If the variable is not initialized the random numbers will all be 0. For example: program testRandoms use RandomNumbers type(randomNumberSequence) :: randomNumbers integer :: i
randomNumbers = new_RandomNumberSequence(seed = 100) do i = 1, 10 print ('(f12.10, 2x)'), getRandomReal(randomNumbers) end do end program testRandoms
Fortran-95 implementation by Robert Pincus NOAA-CIRES Climate Diagnostics Center Boulder, CO 80305 email: Rober.nosp@m.t.Pi.nosp@m.ncus@.nosp@m.colo.nosp@m.rado..nosp@m.edu
A C-program for MT19937, with initialization improved 2002/2/10. Coded by Takuji Nishimura and Makoto Matsumoto. This is a faster version by taking Shawn Cokus's optimization, Matthe Bellew's simplification, Isaku Wada's real version.
Before using, initialize the state by using init_genrand(seed) or init_by_array(init_key, key_length).
Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura, All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Any feedback is very welcome. http://www.math.keio.ac.jp/matumoto/emt.html email: matum.nosp@m.oto@.nosp@m.math..nosp@m.keio.nosp@m..ac.j.nosp@m.p
interface mersennetwister_mod::new_randomnumbersequence |
Definition at line 122 of file mersennetwister.F90.
Public Member Functions | |
type(randomnumbersequence) function | initialize_scalar (seed) |
type(randomnumbersequence) function | initialize_vector (seed) |
type(randomnumbersequence) function initialize_scalar | ( | integer, intent(in) | seed | ) |
Definition at line 189 of file mersennetwister.F90.
type(randomnumbersequence) function initialize_vector | ( | integer, dimension(0:), intent(in) | seed | ) |
Definition at line 207 of file mersennetwister.F90.
type mersennetwister_mod::randomnumbersequence |
The type containing the state variable.
Definition at line 116 of file mersennetwister.F90.
Public Attributes | |
integer | currentelement |
integer, dimension(0:blocksize -1) | state |
integer currentelement |
Definition at line 117 of file mersennetwister.F90.
integer, dimension(0:blocksize -1) state |
Definition at line 118 of file mersennetwister.F90.
subroutine, public finalize_randomnumbersequence | ( | type(randomnumbersequence), intent(inout) | twister | ) |
Definition at line 313 of file mersennetwister.F90.
integer function, public getrandomint | ( | type(randomnumbersequence), intent(inout) | twister | ) |
Generate a random integer on the interval [0,0xffffffff].
Equivalent to genrand_int32 in the C code. Fortran doesn't have a type that's unsigned like C does, so this is integers in the range -2**31 - 2**31 All functions for getting random numbers call this one, then manipulate the result
Definition at line 270 of file mersennetwister.F90.
integer function, public getrandompositiveint | ( | type(randomnumbersequence), intent(inout) | twister | ) |
Generate a random integer on the interval [0,0x7fffffff] or [0,2**31]. Equivalent to genrand_int31 in the C code.
Definition at line 284 of file mersennetwister.F90.
real(r8_kind) function, public getrandomreal | ( | type(randomnumbersequence), intent(inout) | twister | ) |
Generate a random number on [0,1] Equivalent to genrand_real1 in the C code. The result is stored as double precision but has 32 bit resolution.
Definition at line 299 of file mersennetwister.F90.
|
private |
Definition at line 189 of file mersennetwister.F90.
|
private |
Definition at line 207 of file mersennetwister.F90.
|
private |
Definition at line 136 of file mersennetwister.F90.
|
private |
Definition at line 154 of file mersennetwister.F90.
|
private |
Definition at line 174 of file mersennetwister.F90.
|
private |
Definition at line 143 of file mersennetwister.F90.
|
private |
least significant r bits (0x7fffffffUL)
Definition at line 103 of file mersennetwister.F90.
|
private |
Definition at line 103 of file mersennetwister.F90.
|
private |
constant vector a (0x9908b0dfUL)
Definition at line 103 of file mersennetwister.F90.
|
private |
(0x9d2c5680UL)
Definition at line 109 of file mersennetwister.F90.
|
private |
(0xefc60000UL)
Definition at line 109 of file mersennetwister.F90.
|
private |
most significant w-r bits (0x80000000UL)
Definition at line 103 of file mersennetwister.F90.