bmit
March 30, 2023, 2:35pm
1
I looked around and didn’t see any Julia tools for calculating the permanent of a matrix. Does anyone know of anything? I’m particularly interested in the permanent of binary matrices for counting applications.
I did find this discussion:
Any idea on how to improve the following code for computing the permanent of a matrix?
I used the Glynn formula where delta is obtained via Gray code.
# from https://stackoverflow.com/questions/34236332/c-code-for-generating-next-bit-to-flip-in-a-gray-code
function grayBitToFlip(n::Int)
n1 = (n-1) ⊻ ((n-1)>>1)
n2 = n ⊻ (n>>1)
d = n1 ⊻ n2
j = 0
while d>0
d >>= 1
j += 1
end
j
end
function perm(A::AbstractMatrix{T}) where T
n,m = size(A)
if (n == m)
D = Int8(1)
δ = [Int8(2) …
bmit
March 30, 2023, 2:44pm
3
Note to self for next time: try add Permanents
nilshg
March 30, 2023, 2:46pm
4
I used the JuliaHub search functionality.
1 Like
bmit
March 31, 2023, 12:42pm
5
Very neat. I didn’t know that existed. Thanks again.
