simplified halto procedure (still needs testing)

This commit is contained in:
Martin Diehl 2018-02-21 18:47:39 +01:00
parent 98df2d1427
commit ae27660e86
1 changed files with 232 additions and 388 deletions

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@ -161,10 +161,8 @@ module math
math_rotate_forward3333, &
math_limit
private :: &
halton, &
halton_memory, &
halton_ndim_set, &
halton_seed_set
math_check, &
halton
contains
@ -217,8 +215,7 @@ subroutine math_init
call random_seed(put = randInit)
call halton_seed_set(int(randInit(1), pInt))
call halton_ndim_set(3_pInt)
randTest = halton(4,seed = randTest(1))
call math_check()
@ -283,7 +280,7 @@ subroutine math_check
endif
! +++ check rotation sense of q and R +++
call halton(3_pInt,v) ! random vector
v = halton(3_pInt) ! random vector
R = math_qToR(q)
if (any(abs(math_mul33x3(R,v) - math_qRot(q,v)) > tol_math_check)) then
write (error_msg, '(a)' ) 'R(q)*v has different sense than q*v'
@ -1237,7 +1234,7 @@ function math_qRand()
real(pReal), dimension(4) :: math_qRand
real(pReal), dimension(3) :: rnd
call halton(3_pInt,rnd)
rnd = halton(3_pInt)
math_qRand = [cos(2.0_pReal*PI*rnd(1))*sqrt(rnd(3)), &
sin(2.0_pReal*PI*rnd(2))*sqrt(1.0_pReal-rnd(3)), &
cos(2.0_pReal*PI*rnd(2))*sqrt(1.0_pReal-rnd(3)), &
@ -1760,7 +1757,7 @@ function math_sampleRandomOri()
implicit none
real(pReal), dimension(3) :: math_sampleRandomOri, rnd
call halton(3_pInt,rnd)
rnd = halton(3_pInt)
math_sampleRandomOri = [rnd(1)*2.0_pReal*PI, &
acos(2.0_pReal*rnd(2)-1.0_pReal), &
rnd(3)*2.0_pReal*PI]
@ -1793,7 +1790,7 @@ function math_sampleGaussOri(center,FWHM)
cosScatter = cos(scatter)
do
call halton(5_pInt,rnd)
rnd = halton(5_pInt)
rnd(1:3) = 2.0_pReal*rnd(1:3)-1.0_pReal ! expand 1:3 to range [-1,+1]
disturb = [ scatter * rnd(1), & ! phi1
sign(1.0_pReal,rnd(2))*acos(cosScatter+(1.0_pReal-cosScatter)*rnd(4)), & ! Phi
@ -1853,7 +1850,7 @@ function math_sampleFiberOri(alpha,beta,FWHM)
! ---# rotation matrix about fiber axis (random angle) #---
do
call halton(6_pInt,rnd)
rnd = halton(6_pInt)
fRot = math_EulerAxisAngleToR(fiberInS,rnd(1)*2.0_pReal*pi)
! ---# rotation about random axis perpend to fiber #---
@ -1909,7 +1906,7 @@ real(pReal) function math_sampleGaussVar(meanvalue, stddev, width)
myWidth = merge(width,3.0_pReal,present(width)) ! use +-3*sigma as default value for scatter if not given
do
call halton(2_pInt, rnd)
rnd = halton(2_pInt)
scatter = myWidth * (2.0_pReal * rnd(1) - 1.0_pReal)
if (rnd(2) <= exp(-0.5_pReal * scatter ** 2.0_pReal)) exit ! test if scattered value is drawn
enddo
@ -2286,32 +2283,6 @@ pure function math_invariantsSym33(m)
end function math_invariantsSym33
!--------------------------------------------------------------------------------------------------
!> @brief computes the next element in the Halton sequence.
!> @author John Burkardt
!--------------------------------------------------------------------------------------------------
subroutine halton(ndim, r)
implicit none
integer(pInt), intent(in) :: ndim !< dimension of the element
real(pReal), intent(out), dimension(ndim) :: r !< next element of the current Halton sequence
integer(pInt), dimension(ndim) :: base
integer(pInt) :: seed
integer(pInt), dimension(1) :: value_halton
call halton_memory ('GET', 'SEED', 1_pInt, value_halton)
seed = value_halton(1)
call halton_memory ('GET', 'BASE', ndim, base)
call i_to_halton (seed, base, ndim, r)
value_halton(1) = 1_pInt
call halton_memory ('INC', 'SEED', 1_pInt, value_halton)
!--------------------------------------------------------------------------------------------------
contains
!-------------------------------------------------------------------------------------------------
!> @brief computes an element of a Halton sequence.
!> @details Only the absolute value of SEED is considered. SEED = 0 is allowed, and returns R = 0.
@ -2322,136 +2293,27 @@ subroutine halton(ndim, r)
!> @details multi-dimensional integrals, Numerische Mathematik, Volume 2, pages 84-90, 1960.
!> @author John Burkardt
!-------------------------------------------------------------------------------------------------
subroutine i_to_halton (seed, base, ndim, r)
use IO, only: &
IO_error
function halton(ndim, seed)
implicit none
integer(pInt), intent(in) :: &
ndim, & !< dimension of the sequence
seed !< index of the desired element
integer(pInt), intent(in), dimension(ndim) :: base !< Halton bases
real(pReal), intent(out), dimension(ndim) :: r !< the SEED-th element of the Halton sequence for the given bases
real(pReal), dimension(ndim) :: base_inv
ndim !< dimension of the sequence
real(pReal), intent(in), optional :: &
seed !< seed value [0.0,1.0]
real(pReal), dimension(ndim) :: &
halton
integer(pInt), save :: &
start, &
current
real(pReal), dimension(ndim) :: &
base_inv
integer(pInt), dimension(ndim) :: &
digit, &
seed2
seed2 = abs(seed)
r = 0.0_pReal
if (any (base(1:ndim) <= 1_pInt)) call IO_error(error_ID=405_pInt)
base_inv(1:ndim) = 1.0_pReal / real (base(1:ndim), pReal)
do while ( any ( seed2(1:ndim) /= 0_pInt) )
digit(1:ndim) = mod ( seed2(1:ndim), base(1:ndim))
r(1:ndim) = r(1:ndim) + real ( digit(1:ndim), pReal) * base_inv(1:ndim)
base_inv(1:ndim) = base_inv(1:ndim) / real ( base(1:ndim), pReal)
seed2(1:ndim) = seed2(1:ndim) / base(1:ndim)
enddo
end subroutine i_to_halton
end subroutine halton
!--------------------------------------------------------------------------------------------------
!> @brief sets or returns quantities associated with the Halton sequence.
!> @details If action_halton is 'SET' and action_halton is 'BASE', then NDIM is input, and
!> @details is the number of entries in value_halton to be put into BASE.
!> @details If action_halton is 'SET', then on input, value_halton contains values to be assigned
!> @details to the internal variable.
!> @details If action_halton is 'GET', then on output, value_halton contains the values of
!> @details the specified internal variable.
!> @details If action_halton is 'INC', then on input, value_halton contains the increment to
!> @details be added to the specified internal variable.
!> @author John Burkardt
!--------------------------------------------------------------------------------------------------
subroutine halton_memory (action_halton, name_halton, ndim, value_halton)
use IO, only: &
IO_lc
implicit none
character(len = *), intent(in) :: &
action_halton, & !< desired action: GET the value of a particular quantity, SET the value of a particular quantity, INC the value of a particular quantity (only for SEED)
name_halton !< name of the quantity: BASE: Halton base(s), NDIM: spatial dimension, SEED: current Halton seed
integer(pInt), dimension(*), intent(inout) :: value_halton
integer(pInt), allocatable, save, dimension(:) :: base
logical, save :: first_call = .true.
integer(pInt), intent(in) :: ndim !< dimension of the quantity
integer(pInt), save :: ndim_save = 0_pInt, seed = 1_pInt
integer(pInt) :: i
if (first_call) then
ndim_save = 1_pInt
allocate(base(ndim_save))
base(1) = 2_pInt
first_call = .false.
endif
!--------------------------------------------------------------------------------------------------
! Set
actionHalton: if(IO_lc(action_halton(1:1)) == 's') then
nameSet: if(IO_lc(name_halton(1:1)) == 'b') then
if(ndim_save /= ndim) ndim_save = ndim
base = value_halton(1:ndim)
elseif(IO_lc(name_halton(1:1)) == 'n') then nameSet
if(ndim_save /= value_halton(1)) then
ndim_save = value_halton(1)
base = [(prime(i),i=1_pInt,ndim_save)]
else
ndim_save = value_halton(1)
endif
elseif(IO_lc(name_halton(1:1)) == 's') then nameSet
seed = value_halton(1)
endif nameSet
!--------------------------------------------------------------------------------------------------
! Get
elseif(IO_lc(action_halton(1:1)) == 'g') then actionHalton
nameGet: if(IO_lc(name_halton(1:1)) == 'b') then
if(ndim /= ndim_save) then
ndim_save = ndim
base = [(prime(i),i=1_pInt,ndim_save)]
endif
value_halton(1:ndim_save) = base(1:ndim_save)
elseif(IO_lc(name_halton(1:1)) == 'n') then nameGet
value_halton(1) = ndim_save
elseif(IO_lc(name_halton(1:1)) == 's') then nameGet
value_halton(1) = seed
endif nameGet
!--------------------------------------------------------------------------------------------------
! Increment
elseif(IO_lc(action_halton(1:1)) == 'i') then actionHalton
if(IO_lc(name_halton(1:1)) == 's') seed = seed + value_halton(1)
endif actionHalton
!--------------------------------------------------------------------------------------------------
contains
!--------------------------------------------------------------------------------------------------
!> @brief returns any of the first 1500 prime numbers.
!> @details n = 0 is legal, returning PRIME = 1.
!> @details Reference:
!> @details Milton Abramowitz and Irene Stegun: Handbook of Mathematical Functions,
!> @details US Department of Commerce, 1964, pages 870-873.
!> @details Daniel Zwillinger: CRC Standard Mathematical Tables and Formulae,
!> @details 30th Edition, CRC Press, 1996, pages 95-98.
!> @author John Burkardt
!--------------------------------------------------------------------------------------------------
integer(pInt) function prime(n)
use IO, only: &
IO_error
implicit none
integer(pInt), intent(in) :: n !< index of the desired prime number
base, &
t
integer(pInt) :: &
i
integer(pInt), dimension(0:1600), parameter :: &
npvec = int([&
prime = int([&
1, &
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, &
31, 37, 41, 43, 47, 53, 59, 61, 67, 71, &
@ -2629,56 +2491,38 @@ subroutine halton_memory (action_halton, name_halton, ndim, value_halton)
13313, 13327, 13331, 13337, 13339, 13367, 13381, 13397, 13399, 13411, &
13417, 13421, 13441, 13451, 13457, 13463, 13469, 13477, 13487, 13499],pInt)
if (n < size(npvec)) then
prime = npvec(n)
if (present(seed)) then
start = int(seed * 1599.0_pReal,pInt) + 1_pInt ! select one prime number to start with
current = 1_pInt
else
call IO_error(error_ID=406_pInt)
current = current + 1_pInt
endif
end function prime
base = [(prime(mod(start,1600_pInt)+i), i=1_pInt, ndim)]
base_inv = 1.0_pReal/real(base,pReal)
end subroutine halton_memory
halton = 0.0_pReal
t = current
do while (any( t /= 0_pInt) )
halton = halton + real(mod(t,base), pReal) * base_inv
base_inv = base_inv / real(base, pReal)
t = t / base
enddo
!--------------------------------------------------------------------------------------------------
!> @brief sets the dimension for a Halton sequence
!> @brief returns any of the first 1600 prime numbers.
!> @details n = 0 is legal, returning PRIME = 1.
!> @details 0 > n > 1600 returns -1
!> @details Reference:
!> @details Milton Abramowitz and Irene Stegun: Handbook of Mathematical Functions,
!> @details US Department of Commerce, 1964, pages 870-873.
!> @details Daniel Zwillinger: CRC Standard Mathematical Tables and Formulae,
!> @details 30th Edition, CRC Press, 1996, pages 95-98.
!> @author John Burkardt
!--------------------------------------------------------------------------------------------------
subroutine halton_ndim_set(ndim)
implicit none
integer(pInt), intent(in) :: ndim !< dimension of the Halton vectors
integer(pInt) :: value_halton(1)
value_halton(1) = ndim
call halton_memory ('SET', 'NDIM', 1_pInt, value_halton)
end subroutine halton_ndim_set
!--------------------------------------------------------------------------------------------------
!> @brief sets the seed for the Halton sequence.
!> @details Calling HALTON repeatedly returns the elements of the Halton sequence in order,
!> @details starting with element number 1.
!> @details An internal counter, called SEED, keeps track of the next element to return. Each time
!> @details is computed, and then SEED is incremented by 1.
!> @details To restart the Halton sequence, it is only necessary to reset SEED to 1. It might also
!> @details be desirable to reset SEED to some other value. This routine allows the user to specify
!> @details any value of SEED.
!> @details The default value of SEED is 1, which restarts the Halton sequence.
!> @author John Burkardt
!--------------------------------------------------------------------------------------------------
subroutine halton_seed_set(seed)
implicit none
integer(pInt), parameter :: NDIM = 1_pInt
integer(pInt), intent(in) :: seed !< seed for the Halton sequence.
integer(pInt) :: value_halton(ndim)
value_halton(1) = seed
call halton_memory ('SET', 'SEED', NDIM, value_halton)
end subroutine halton_seed_set
end function halton
!--------------------------------------------------------------------------------------------------