The quasi-best MaxN function

General Usage Performance
13

Using some heap-functions and the suggestions of @mikkoku

function MaxN7(cr,N)
    maxn = heapify!(cr[1:N])
    maxn1=maxn[1]
       @inbounds for i in N+1:length(cr)
        e=cr[i]    
        if maxn1 < e
            heappop!(maxn)
            heappush!(maxn,e)
            maxn1=maxn[1]
            end
        end
    sort!(maxn,rev=true)
end

julia> nlargest(2000,re8)==MaxN7(re8,2000)
true

julia> @btime MaxN7($re6,20);
  576.800 μs (1 allocation: 240 bytes)

julia> @btime MaxN7($re8,2000);
  71.938 ms (1 allocation: 15.75 KiB)

julia> @btime nlargest(2000,$re8);
  86.122 ms (2 allocations: 31.50 KiB)
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