mirror of
https://igit.ific.uv.es/alramos/latticegpu.jl.git
synced 2025-05-14 19:23:42 +02:00
115 lines
3 KiB
Julia
115 lines
3 KiB
Julia
###
|
|
### "THE BEER-WARE LICENSE":
|
|
### Alberto Ramos wrote this file. As long as you retain this
|
|
### notice you can do whatever you want with this stuff. If we meet some
|
|
### day, and you think this stuff is worth it, you can buy me a beer in
|
|
### return. <alberto.ramos@cern.ch>
|
|
###
|
|
### file: YMhmc.jl
|
|
### created: Thu Jul 15 11:27:28 2021
|
|
###
|
|
|
|
"""
|
|
|
|
function gauge_action(U, lp::SpaceParm, gp::GaugeParm, ymws::YMworkspace)
|
|
|
|
Returns the value of the Wilson plaquette action for the configuration U.
|
|
"""
|
|
function gauge_action(U, lp::SpaceParm, gp::GaugeParm{T}, ymws::YMworkspace{T}) where T <: AbstractFloat
|
|
|
|
if abs(gp.c0-1) < 1.0E-10
|
|
CUDA.@sync begin
|
|
CUDA.@cuda threads=lp.bsz blocks=lp.rsz krnl_plaq!(ymws.cm, U, lp)
|
|
end
|
|
else
|
|
CUDA.@sync begin
|
|
CUDA.@cuda threads=lp.bsz blocks=lp.rsz krnl_impr!(ymws.cm, U, gp.c0, (1-gp.c0)/8, lp)
|
|
end
|
|
end
|
|
S = gp.beta*( prod(lp.iL)*lp.npls*(gp.c0 + (1-gp.c0)/8) -
|
|
CUDA.mapreduce(real, +, ymws.cm)/gp.ng )
|
|
|
|
return S
|
|
end
|
|
|
|
function plaquette(U, lp::SpaceParm, gp::GaugeParm, ymws::YMworkspace)
|
|
|
|
CUDA.@sync begin
|
|
CUDA.@cuda threads=lp.bsz blocks=lp.rsz krnl_plaq!(ymws.cm, U, lp)
|
|
end
|
|
|
|
return CUDA.mapreduce(real, +, ymws.cm)/(prod(lp.iL)*lp.npls)
|
|
end
|
|
|
|
function hamiltonian(mom, U, lp, gp, ymws)
|
|
K = CUDA.mapreduce(norm2, +, mom)/2
|
|
V = gauge_action(U, lp, gp, ymws)
|
|
|
|
return K+V
|
|
end
|
|
|
|
function HMC!(U, eps, ns, lp::SpaceParm, gp::GaugeParm, ymws::YMworkspace; noacc=false)
|
|
|
|
ymws.U1 .= U
|
|
|
|
randomize!(ymws.mom, lp, ymws)
|
|
hini = hamiltonian(ymws.mom, U, lp, gp, ymws)
|
|
|
|
OMF4!(ymws.mom, U, eps, ns, lp, gp, ymws)
|
|
|
|
dh = hamiltonian(ymws.mom, U, lp, gp, ymws) - hini
|
|
pacc = exp(-dh)
|
|
|
|
acc = true
|
|
if (noacc)
|
|
return dh, acc
|
|
end
|
|
|
|
if (pacc < 1.0)
|
|
r = rand()
|
|
if (pacc < r)
|
|
U .= ymws.U1
|
|
acc = false
|
|
end
|
|
end
|
|
|
|
return dh, acc
|
|
end
|
|
|
|
function OMF4!(mom, U, eps, ns, lp::SpaceParm, gp::GaugeParm{T}, ymws::YMworkspace{T}) where T <: AbstractFloat
|
|
|
|
r1::T = 0.08398315262876693
|
|
r2::T = 0.2539785108410595
|
|
r3::T = 0.6822365335719091
|
|
r4::T = -0.03230286765269967
|
|
r5::T = 0.5-r1-r3
|
|
r6::T = 1.0-2.0*(r2+r4)
|
|
|
|
ee = eps*gp.beta/gp.ng
|
|
force_gauge(ymws, U, gp.c0, lp)
|
|
for i in 1:ns
|
|
mom .= mom .+ (r1*ee) .* ymws.frc1
|
|
U .= expm.(U, mom, eps*r2)
|
|
|
|
force_gauge(ymws, U, gp.c0, lp)
|
|
mom .= mom .+ (r3*ee) .* ymws.frc1
|
|
U .= expm.(U, mom, eps*r4)
|
|
|
|
force_gauge(ymws, U, gp.c0, lp)
|
|
mom .= mom .+ (r5*ee) .* ymws.frc1
|
|
U .= expm.(U, mom, eps*r6)
|
|
|
|
force_gauge(ymws, U, gp.c0, lp)
|
|
mom .= mom .+ (r5*ee) .* ymws.frc1
|
|
U .= expm.(U, mom, eps*r4)
|
|
|
|
force_gauge(ymws, U, gp.c0, lp)
|
|
mom .= mom .+ (r3*ee) .* ymws.frc1
|
|
U .= expm.(U, mom, eps*r2)
|
|
|
|
force_gauge(ymws, U, gp.c0, lp)
|
|
mom .= mom .+ (r1*ee) .* ymws.frc1
|
|
end
|
|
|
|
return nothing
|
|
end
|