First of all, have a look at the result.
<https://lh3.googleusercontent.com/-anNt-E4P1vM/Vvp-TybegZI/AAAAAAAAABE/ZvDO2xarndMSgKVOXy_hcPd5NTh-7QcEA/s1600/QQ%25E5%259B%25BE%25E7%2589%258720160329210732.png>
My code calculates the evolution of 1-d 2-electron system in the electric
field, some variables are calculated during the evolution.
According to the result of @time evolution, my code must have a
pre-allocation problem. Before you see the long code, i suggest that the
hotspot might be around the Arrays prop_e, \phio, pp. I have learnt that I
can use m = Array(Float64, 1) outside a "for" loop and empty!(m) and
push!(m, new_m) inside the loop to pre-allocate the variable m, but in my
situations, I don't know how to pre-allocate these arrays.
Below is the script (precisely, the main function) itself.
function evolution(ϕ::Array{Complex{Float64}, 2},
ele::Array{Float64, 1}, dx::Float64, dt::Float64,
flags::Tuple{Int64, Int64, Int64, Int64})
ϕg = copy(ϕ)
FFTW.set_num_threads(8)
ns = length( ϕ[:, 1] )
x = get_x(ns, dx)
p = get_p(ns, dx)
if flags[4] == 1
pp = similar(p)
A = -cumsum(ele) * dt
A² = A.*A
##### splitting
r_sp = 150.0
δ_sp = 5.0
splitter = Array(Float64, ns, ns)
end
nt = length( ele )
# ##### Pre-allocate result and temporary arrays
#if flags[1] == 1
σ = zeros(Complex128, nt)
#end
#if flags[2] == 1
a = zeros(Float64, nt)
#end
#if flags[3] == 1
r_ionization = 20.0
n1 = round(Int, ns/2 - r_ionization/dx)
n2 = round(Int, ns/2 + r_ionization/dx)
ip = zeros(Float64, nt)
#end
##### FFT plan
p_fft! = plan_fft!( similar(ϕ), flags=FFTW.MEASURE )
prop_x = similar( ϕ )
prop_p = similar( prop_x )
prop_e = similar( prop_x )
# this two versions just cost the same time
xplusy = Array(Float64, ns, ns)
#xplusy = Array( Float64, ns^2)
##### absorb boundary
r_a = ns * dx /2 - 50.0
δ = 10.0
absorb = Array(Float64, ns, ns)
k0 = 2π / (ns * dx)
@inbounds for j in 1:ns
@inbounds for i in 1:ns
prop_x[i, j] = exp( -im * get_potential(x[i], x[j]) * dt / 2 )
prop_p[i, j] = exp( -im * (p[i]^2 + p[j]^2)/2 * dt )
xplusy[i, j] = x[i] + x[j]
absorb[i, j] = (1.0 - get_out(x[i], r_a, δ ))* (1.0 -
get_out(x[j],
r_a, δ))
end
end
if flags[2] == 1
pvpx = Array(Float64, ns, ns)
@inbounds for j in 1:ns
@inbounds for i in 1:ns
pvpx[i, j] = get_pvpx(x[i], x[j])
end
end
end
if flags[4] == 1
ϕo = zeros(Complex128, ns, ns)
ϕp = zeros(Complex128, ns, ns)
@inbounds for j in 1:ns
@inbounds for i in 1:ns
splitter[i, j] = get_out(x[i], r_sp, δ_sp) * get_out(x[j],
r_sp, δ_sp)
end
end
end
for i in 1:nt
for j in eachindex(ϕ)
prop_e[j] = exp( -im * ele[i] * xplusy[j] * dt/2.0)
end
for j in eachindex(ϕ)
ϕ[j] *= prop_x[j] * prop_e[j]
end
p_fft! * ϕ
for j in eachindex(ϕ)
ϕ[j] *= prop_p[j]
end
p_fft! \ ϕ
for j in eachindex(ϕ)
ϕ[j] *= prop_x[j] * prop_e[j]
end
########## autocorrelation function σ(t)
if flags[1] == 1
for j in eachindex(ϕ)
σ[i] += conj(ϕg[j]) * ϕ[j]
end
end
########## dipole acceleration a(t)
if flags[2] == 1
for j in eachindex(ϕ)
a[i] += abs(ϕ[j])^2 * (pvpx[j] + 2ele[i])
end
end
########## ionization probability ip(t)
if flags[3] == 1
for j1 in n1:n2
for j2 in 1:ns
ip[i] += abs( ϕ[j2+ns*(j1-1)] )^2
end
end
for j1 in [1:n1-1; n2+1:ns]
for j2 in n1:n2
ip[i] += abs( ϕ[j2+ns*(j1-1)] )^2
end
end
end
########## get momentum
if flags[4] == 1
for j in eachindex(ϕo)
ϕo[j] = ϕ[j] * splitter[j] * exp( -im * A[i]*xplusy[j] )
end
for j in eachindex(p)
pp[j] = p[j]^2 /2 * (nt-i) - p[j] *sum( A[i:nt] ) + sum(
A²[1:nt] ) /2
end
for j2 in 1:ns
for j1 in 1:ns
ϕo[j1, j2] = ϕo[j1, j2] * exp( -im * (pp[j1] + pp[j2])
* dt)
end
end
p_fft! * ϕo
for j in eachindex(ϕp)
ϕp[j] += ϕo[j]
end
end
########## absorb boundary
if mod(i, 300) == 0
for j in eachindex(ϕ)
ϕ[j] *= absorb[j]
end
end
if (mod(i, 500) == 0)
println("i = $i")
flush(STDOUT)
end
end
σ *= dx^2
a *= dx^2
ip *= dx^2
save("data/fs.jld", "ϕ", ϕ)
if flags[1] == 1
save("data/sigma.jld", "σ", σ)
end
if flags[2] == 1
save("data/a.jld", "a", a)
end
if flags[3] == 1
save("data/ip.jld", "ip", ip)
end
if flags[4] == 1
save("data/pf.jld", "ϕp", ϕp)
end
#return σ, a, ip, ϕ
nothing
end