RandomIterator

RandomIterator.ipynb

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      "source": "using Distributions\nusing BenchmarkTools\n\nstruct RandomIterator <: AbstractArray{Float64,1}\n    count::Int64\nend\n@inline Base.start(::RandomIterator) = 1\n@inline Base.next(R::RandomIterator, state) = (rand(), state+1)\n@inline Base.done(R::RandomIterator, state) = state > R.count\n@inline Base.eltype(::Type{RandomIterator}) = Float64\n@inline Base.length(R::RandomIterator) = R.count\n@inline Base.getindex(R::RandomIterator, i::Int) = rand()\n@inline Base.endof(R::RandomIterator) = length(R)\n@inline Base.size(R::RandomIterator) = (length(R), )\n\nfunction binomial_rv_for(n, p)\n    X = Vector{Int}(n)\n    for i in 1:n\n        X[i] = Int(rand() < p)\n    end\n    X\nend\nbinomial_rv_for(10, 0.5)\n\nfunction binomial_rv_inbounds_for(n, p)\n    X = Vector{Int}(n)\n    @inbounds for i in 1:n\n        X[i] = Int(rand() < p)\n    end\n    X\nend\nbinomial_rv_inbounds_for(10, 0.5)\n\nbinomial_rv_array(n, p) = Int.(rand(n) .< p)\nbinomial_rv_array(10, 0.5)\n\nbinomial_rv_Distributions(n, p) = rand(Bernoulli(p), n)\nbinomial_rv_Distributions(10, 0.5)\n\nbinomial_rv_RandomIterator(n, p) = Int.(RandomIterator(n) .< p)\nbinomial_rv_RandomIterator(10, 0.5)\n\nn, p = 10^7, 0.5\n@btime binomial_rv_for(n, p)\n@btime binomial_rv_inbounds_for(n, p)\n@btime binomial_rv_array(n, p)\n@btime binomial_rv_Distributions(n, p)\n@btime binomial_rv_RandomIterator(n, p)\n;",
      "execution_count": 1,
      "outputs": [
        {
          "output_type": "stream",
          "text": "  49.768 ms (2 allocations: 76.29 MiB)\n  49.929 ms (2 allocations: 76.29 MiB)\n  70.532 ms (29 allocations: 152.59 MiB)\n  82.841 ms (3 allocations: 76.29 MiB)\n  48.101 ms (46 allocations: 76.30 MiB)\n",
          "name": "stdout"
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      "source": "gc()\n@benchmark binomial_rv_for(n, p)",
      "execution_count": 2,
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        {
          "output_type": "execute_result",
          "execution_count": 2,
          "data": {
            "text/plain": "BenchmarkTools.Trial: \n  memory estimate:  76.29 MiB\n  allocs estimate:  2\n  --------------\n  minimum time:     44.690 ms (0.35% GC)\n  median time:      50.667 ms (11.75% GC)\n  mean time:        51.363 ms (12.70% GC)\n  maximum time:     110.908 ms (59.90% GC)\n  --------------\n  samples:          98\n  evals/sample:     1"
          },
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      "cell_type": "code",
      "source": "gc()\n@benchmark binomial_rv_inbounds_for(n, p)",
      "execution_count": 3,
      "outputs": [
        {
          "output_type": "execute_result",
          "execution_count": 3,
          "data": {
            "text/plain": "BenchmarkTools.Trial: \n  memory estimate:  76.29 MiB\n  allocs estimate:  2\n  --------------\n  minimum time:     45.690 ms (0.89% GC)\n  median time:      51.288 ms (11.76% GC)\n  mean time:        52.383 ms (12.82% GC)\n  maximum time:     112.311 ms (59.96% GC)\n  --------------\n  samples:          96\n  evals/sample:     1"
          },
          "metadata": {}
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      ]
    },
    {
      "metadata": {
        "trusted": true
      },
      "cell_type": "code",
      "source": "gc()\n@benchmark binomial_rv_RandomIterator(n, p)",
      "execution_count": 4,
      "outputs": [
        {
          "output_type": "execute_result",
          "execution_count": 4,
          "data": {
            "text/plain": "BenchmarkTools.Trial: \n  memory estimate:  76.30 MiB\n  allocs estimate:  46\n  --------------\n  minimum time:     43.460 ms (0.40% GC)\n  median time:      49.451 ms (12.32% GC)\n  mean time:        50.154 ms (13.40% GC)\n  maximum time:     111.025 ms (60.43% GC)\n  --------------\n  samples:          100\n  evals/sample:     1"
          },
          "metadata": {}
        }
      ]
    },
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        "trusted": true
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      "cell_type": "code",
      "source": "",
      "execution_count": null,
      "outputs": []
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