# Benchmarks of Multidimensional Stack Implementations in Julia

Re-posted from: http://www.stochasticlifestyle.com/233-2/

Datastructures.jl claims it’s fast. How does it do? I wrote some quick codes to check it out. What I wanted to do is find out which algorithm does best for implementing a stack where each element is three integers. I tried filling a pre-allocated array, pushing into three separate vectors, and different implementations of the stack from the DataStructures.jl package.

function baseline()
stack = Array{Int64,2}(1000000,3)
for i=1:1000000,j=1:3
stack[i,j]=i
end
end
function baseline2()
stack = Array{Int64,2}(1000000,3)
for j=1:3,i=1:1000000
stack[i,j]=i
end
end
function f0()
stack = Array{Int64}(1000000,3)
for i = 1:1000000
stack[i,:] = [i,i,i]
end
end
function f02()
stack = Array{Int64}(3,1000000)
for i = 1:1000000
stack[:,i] = [i;i;i]
end
end
function f1()
stack1 = Vector{Int64}(1)
stack2 = Vector{Int64}(1)
stack3 = Vector{Int64}(1)
for i = 1:1000000
push!(stack1,i)
push!(stack2,i)
push!(stack3,i)
end
end
function f2()
stack1 = Stack(Int)
stack2 = Stack(Int)
stack3 = Stack(Int)
for i = 1:1000000
push!(stack1,i)
push!(stack2,i)
push!(stack3,i)
end
end
function f3()
stack = Stack{}(Tuple{Int64,Int64,Int64})
for i = 1:1000000
push!(stack,(i,i,i))
end
end
function f4()
stack = Stack{}(Vector{Int64})
for i = 1:1000000
push!(stack,[i,i,i])
end
end
using Benchmark
using DataStructures
base = benchmark(baseline,"baseline",1000)
println(base)
base2 = benchmark(baseline2,"baseline2",1000)
println(base2)
df0 = benchmark(f0,"array",1000)
println(df0)
df02 = benchmark(f02,"arrayTranspose",1000)
println(df02)
df1 = benchmark(f1,"vectorStack",1000)
println(df1)
df2 = benchmark(f2,"dsStacks",1000)
println(df2)
df3 = benchmark(f3,"dsStackTuple",1000)
println(df3)
df4 = benchmark(f4,"dsStackVector",1000)
println(df4)

The results were as follows:

| Row | Category   | Benchmark  | Iterations | TotalWall | AverageWall |
|-----|------------|------------|------------|-----------|-------------|
| 1   | "baseline" | "baseline" | 1000       | 11.7169   | 0.0117169   |

| Row | MaxWall   | MinWall    | Timestamp             |
|-----|-----------|------------|-----------------------|
| 1   | 0.0158455 | 0.00978837 | "2016-02-29 23:23:51" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category    | Benchmark   | Iterations | TotalWall | AverageWall |
|-----|-------------|-------------|------------|-----------|-------------|
| 1   | "baseline2" | "baseline2" | 1000       | 9.84362   | 0.00984362  |

| Row | MaxWall   | MinWall    | Timestamp             |
|-----|-----------|------------|-----------------------|
| 1   | 0.0126953 | 0.00694176 | "2016-02-29 23:24:01" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category | Benchmark | Iterations | TotalWall | AverageWall | MaxWall  |
|-----|----------|-----------|------------|-----------|-------------|----------|
| 1   | "array"  | "array"   | 1000       | 114.288   | 0.114288    | 0.172499 |

| Row | MinWall   | Timestamp             |
|-----|-----------|-----------------------|
| 1   | 0.0775942 | "2016-02-29 22:45:42" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category         | Benchmark        | Iterations | TotalWall |
|-----|------------------|------------------|------------|-----------|
| 1   | "arrayTranspose" | "arrayTranspose" | 1000       | 110.981   |

| Row | AverageWall | MaxWall  | MinWall   | Timestamp             |
|-----|-------------|----------|-----------|-----------------------|
| 1   | 0.110981    | 0.183495 | 0.0741138 | "2016-02-29 22:47:34" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category      | Benchmark     | Iterations | TotalWall | AverageWall |
|-----|---------------|---------------|------------|-----------|-------------|
| 1   | "vectorStack" | "vectorStack" | 1000       | 34.4623   | 0.0344623   |

| Row | MaxWall   | MinWall   | Timestamp             |
|-----|-----------|-----------|-----------------------|
| 1   | 0.0455326 | 0.0285367 | "2016-02-29 22:48:09" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category   | Benchmark  | Iterations | TotalWall | AverageWall |
|-----|------------|------------|------------|-----------|-------------|
| 1   | "dsStacks" | "dsStacks" | 1000       | 38.0762   | 0.0380762   |

| Row | MaxWall   | MinWall   | Timestamp             |
|-----|-----------|-----------|-----------------------|
| 1   | 0.0508213 | 0.0303853 | "2016-02-29 22:48:47" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category       | Benchmark      | Iterations | TotalWall | AverageWall |
|-----|----------------|----------------|------------|-----------|-------------|
| 1   | "dsStackTuple" | "dsStackTuple" | 1000       | 19.3516   | 0.0193516   |

| Row | MaxWall   | MinWall   | Timestamp             |
|-----|-----------|-----------|-----------------------|
| 1   | 0.0296347 | 0.0140451 | "2016-02-29 22:49:06" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category        | Benchmark       | Iterations | TotalWall |
|-----|-----------------|-----------------|------------|-----------|
| 1   | "dsStackVector" | "dsStackVector" | 1000       | 184.126   |

| Row | AverageWall | MaxWall  | MinWall | Timestamp             |
|-----|-------------|----------|---------|-----------------------|
| 1   | 0.184126    | 0.227575 | 0.16454 | "2016-02-29 22:52:11" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |
1x12 DataFrames.DataFrame
| Row | Category      | Benchmark     | Iterations | TotalWall | AverageWall |
|-----|---------------|---------------|------------|-----------|-------------|
| 1   | "vectorTuple" | "vectorTuple" | 1000       | 23.65     | 0.02365     |

| Row | MaxWall   | MinWall   | Timestamp             |
|-----|-----------|-----------|-----------------------|
| 1   | 0.0375346 | 0.0200302 | "2016-02-29 23:29:45" |

| Row | JuliaHash                                  | CodeHash | OS        |
|-----|--------------------------------------------|----------|-----------|
| 1   | "a2f713dea5ac6320d8dcf2835ac4a37ea751af05" | NA       | "Windows" |

| Row | CPUCores |
|-----|----------|
| 1   | 8        |

Things to learn from this are:

• Using a tuple is by far the fastest.
• Datastructures.jl does beat out all except the pre-allocated array
• The standard vector is pretty close to the DataStructures.jl result

The end result is: use arrays when you can pre-allocate and need mutability, but if you want to throw and retrieve things from a dynamic data structure, using tuples is key. Datastructures.jl has some nice features and (obviously) implementations of data structures, and although they are slightly faster than the native implementation, don’t expect a massive speedup. Still, it’s a well-made package you should try out.

The post Benchmarks of Multidimensional Stack Implementations in Julia appeared first on Stochastic Lifestyle.