I have a sparse array in Julia and would like to iterate over its non-zero entries. What's a good way of doing this?
So far, I have:
using SparseArrays
a = sprandn(20,20,0.3)
for (x,y,v) in a
print(x,y,v)
end
The findnz
function returns a tuple containing arrays of the x, y, and value components of the sparse matrix. That is,
findnz(a) gives ([x1, x2, x3, ...], [y1, y2, y3, ...], [v1, v2, v3, ...])
You can use this like an iterator as follows:
for (x,y,v) in zip(findnz(a)...)
println(x,' ',y,' ',v)
end