Finding sub-arrays in an array?

General Usage
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1

I’m putting this here because this is a chemistry usage but it’s not really a chemistry-specific case.

I have an array that has a bunch of states formatted like this:

1.0 1.0 0.0 1.0 0.0 1.0 6380.35
1.0 1.0 1.0 1.0 0.0 1.0 6316.91
2.0 1.0 1.0 2.0 0.0 2.0 6444.27
2.0 1.0 2.0 1.0 0.0 1.0 11086.5

For any given line, 1:3 is a description of one state, 4:6 is the description of a second state, and 7 is the frequency of the difference.

I have created a list of all the states (which is all the values 1:3 and 4:6 listed in an nx3 array) and of all the unique states, and I need to identify which states only appear once in the list. However,

findall(isequal(unst[1,:]), states[1:3,:])

Is not working – it provides an empty Cartesian index

CartesianIndex{2}

Preferably, I would be able to find the index of every unique state in the overall nx7 list. Does anyone know how to do this?

Thanks!

2

The issue is that isequal operates on the entire array, rather than columnwise like you seem to want. SInce the entire matrix does not match unst[1,:], you get a single false as a result.

Does

findall(isequal(unst[1,:]), eachcol(@view(states[1:3, :]))) # @view is optional

do what you want? This should slice the matrix into each 3-tall column and compare each of those to unst[1, :].

For example,

julia> findall(isequal([1;2;3]), eachcol([1;1;1;; 1;2;3;; 3;2;1;; 2;2;2;;]))
1-element Vector{Int64}:
 2
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