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Percolation/Bond percolation: Difference between revisions
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Line 768:
"p=10/10 -> 0.0000"
</pre>
=={{header|Julia}}==
{{works with|Julia|0.6}}
{{trans|Python}}
<lang julia>using Distributions
struct Grid
cells::BitArray{2}
hwall::BitArray{2}
vwall::BitArray{2}
end
function Grid(p::AbstractFloat, m::Integer=10, n::Integer=10)
cells = fill(false, m, n)
hwall = rand(Bernoulli(p), m + 1, n)
vwall = rand(Bernoulli(p), m, n + 1)
vwall[:, 1] = true
vwall[:, end] = true
return Grid(cells, hwall, vwall)
end
function Base.show(io::IO, g::Grid)
H = (" .", " _")
V = (":", "|")
C = (" ", "#")
ind = findfirst(g.cells[end, :] .& .!g.hwall[end, :])
percolated = !iszero(ind)
println(io, "$(size(g.cells, 1))×$(size(g.cells, 2)) $(percolated ? "Percolated" : "Not percolated") grid")
for r in 1:size(g.cells, 1)
println(io, " ", join(H[w+1] for w in g.hwall[r, :]))
println(io, " $(r % 10)) ", join(V[w+1] * C[c+1] for (w, c) in zip(g.vwall[r, :], g.cells[r, :])))
end
println(io, " ", join(H[w+1] for w in g.hwall[end, :]))
if percolated
println(io, " !) ", " " ^ (ind - 1), '#')
end
end
function floodfill!(m::Integer, n::Integer, cells::AbstractMatrix{<:Integer},
hwall::AbstractMatrix{<:Integer}, vwall::AbstractMatrix{<:Integer})
# fill cells
cells[m, n] = true
percolated = false
# bottom
if m < size(cells, 1) && !hwall[m+1, n] && !cells[m+1, n]
percolated = percolated || floodfill!(m + 1, n, cells, hwall, vwall)
# The Bottom
elseif m == size(cells, 1) && !hwall[m+1, n]
return true
end
# left
if n > 1 && !vwall[m, n] && !cells[m, n-1]
percolated = percolated || floodfill!(m, n - 1, cells, hwall, vwall)
end
# right
if n < size(cells, 2) && !vwall[m, n+1] && !cells[m, n+1]
percolated = percolated || floodfill!(m, n + 1, cells, hwall, vwall)
end
# top
if m > 1 && !hwall[m, n] && !cells[m-1, n]
percolated = percolated || floodfill!(m - 1, n, cells, hwall, vwall)
end
return percolated
end
function pourontop!(g::Grid)
m, n = 1, 1
percolated = false
while !percolated && n ≤ size(g.cells, 2)
percolated = !g.hwall[m, n] && floodfill!(m, n, g.cells, g.hwall, g.vwall)
n += 1
end
return percolated
end
function main(probs, nrep::Integer=1000)
sampleprinted = false
pcount = zeros(Int, size(probs))
for (i, p) in enumerate(probs), _ in 1:nrep
g = Grid(p)
percolated = pourontop!(g)
if percolated
pcount[i] += 1
if !sampleprinted
println(g)
sampleprinted = true
end
end
end
return pcount ./ nrep
end
probs = collect(10:-1:0) ./ 10
percprobs = main(probs)
println("Fraction of 1000 tries that percolate through:")
for (pr, pp) in zip(probs, percprobs)
@printf("\tp = %.3f ⇒ freq. = %5.3f\n", pr, pp)
end</lang>
{{out}}
<pre>10×10 Percolated grid
_ . . _ _ _ . _ . .
1) | |#:#| | : | : | :
_ _ . _ _ _ _ _ . _
2) | | |#| : : | : | |
_ _ . _ _ _ _ _ _ .
3) | | |#:#| : | : | :
. _ _ . _ _ _ . _ _
4) | | | :#: : | | | |
. _ _ . _ _ _ . _ _
5) | | : |#| | : | | :
_ . _ . _ _ . . . _
6) | | | |#| | | | | |
. . _ . _ _ _ . . .
7) | |#:#:#: | | : | |
_ . . _ . . . . _ _
8) | |#|#| | | : | | |
_ . . _ _ _ . _ _ _
9) |#:#|#| : : | : | |
. _ _ _ _ . _ _ _ .
0) |#: | : | | | : : |
. . _ _ _ _ . _ _ _
!) #
Fraction of 1000 tries that percolate through:
p = 1.000 ⇒ freq. = 0.000
p = 0.900 ⇒ freq. = 0.000
p = 0.800 ⇒ freq. = 0.000
p = 0.700 ⇒ freq. = 0.001
p = 0.600 ⇒ freq. = 0.064
p = 0.500 ⇒ freq. = 0.470
p = 0.400 ⇒ freq. = 0.895
p = 0.300 ⇒ freq. = 0.997
p = 0.200 ⇒ freq. = 1.000
p = 0.100 ⇒ freq. = 1.000
p = 0.000 ⇒ freq. = 1.000</pre>
=={{header|Kotlin}}==
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