using System;

using System.Linq;

namespace NumSharp.Benchmark

{

public static class ArrayTester

{

public static void Access()

{

var A = new int[10000,10000];

int ALength = 10000 * 10000;

for (int idx = 0; idx < ALength;idx++)

{

int dim0 = idx / 10000;

int dim1 = idx % 10000;

A[dim0,dim1] = idx;

}

var watcher1 = new System.Diagnostics.Stopwatch();

watcher1.Start();

for (int idx = 0; idx < ALength;idx++)

{

int dim0 = idx / 10000;

int dim1 = idx % 10000;

int puffer = A[dim0,dim1];

A[dim0,dim1] = puffer;

}

watcher1.Stop();

A = null;

var B = new int[10000][];

B = B.Select(x => new int[10000]).ToArray();

for (int idx = 0; idx < ALength;idx++)

{

int dim0 = idx / 10000;

int dim1 = idx % 10000;

B[dim0][dim1] = idx;

}

for (int idx = 0; idx < ALength;idx++)

{

int dim0 = idx / 10000;

int dim1 = idx % 10000;

B[dim0][dim1] = idx;

}

var watcher2 = new System.Diagnostics.Stopwatch();

watcher2.Start();

for (int idx = 0; idx < ALength;idx++)

{

int dim0 = idx / 10000;

int dim1 = idx % 10000;

int puffer = B[dim0][dim1];

B[dim0][dim1] = puffer;

}

watcher2.Stop();

B = null;

var C = new int[ALength];

C = C.Select((x,idx) => idx).ToArray();

var watcher3 = new System.Diagnostics.Stopwatch();

watcher3.Start();

for (int idx = 0; idx < ALength;idx++)

{

int dim0 = idx / 10000;

int dim1 = idx % 10000;

int puffer = C[idx];

C[idx] = puffer;

}

watcher3.Stop();

}

public static void CheckPlusOperation()

{

var A = new double[1000][];

A = A.Select(x => new double[1000]).Select((x,idx) => x.Select((y,jdx) => (double)(idx + jdx) ).ToArray()).ToArray();

var B = new double[1000][];

B = B.Select(x => new double[1000]).Select((x,idx) => x.Select((y,jdx) => (double)(idx + jdx) ).ToArray()).ToArray();

var watch1 = new System.Diagnostics.Stopwatch();

watch1.Start();

var C = A.Select((x,idx) => x.Select((y,jdx) => y + A[idx][jdx]).ToArray()).ToArray();

watch1.Stop();

A = null;

B = null;

var a = new double[1000*1000];

a = a.Select((x,idx) => (double)idx).ToArray();

var b = new double[1000*1000];

b = b.Select((x,idx) => (double)idx).ToArray();

var watch2 = new System.Diagnostics.Stopwatch();

watch2.Start();

var c = a.Select((x,idx) => x + b[idx]).ToArray();

watch2.Stop();

a = null;

b = null;

}

public static void CheckMatrixMultiplication()

{

var A = new double[1000][];

A = A.Select(x => new double[1000]).Select((x,idx) => x.Select((y,jdx) => (double)(idx + jdx) ).ToArray()).ToArray();

var B = new double[1000][];

B = B.Select(x => new double[1000]).Select((x,idx) => x.Select((y,jdx) => (double)(idx + jdx) ).ToArray()).ToArray();

int numOfLines = A.GetLength(0);

int numOfColumns = A[0].GetLength(0);

int iterator = B[0].GetLength(0);

var result = new double[numOfLines][];

result = result.Select(x => new double[numOfColumns]).ToArray();

var watch1 = new System.Diagnostics.Stopwatch();

watch1.Start();

for (int idx = 0; idx < numOfLines;idx++)

{

for( int jdx = 0; jdx < numOfColumns; jdx++)

{

result[idx][jdx] = 0;

for (int kdx = 0; kdx < iterator; kdx++)

{

result[idx][jdx] += A[idx][kdx] * B[kdx][jdx];

}

}

}

watch1.Stop();

var a = new double[]{1,2,3,4,5,6,7,8,9};

var b = new double[]{8,0,4,2,1,0,8,1,0};

var c = new double[9];

for (int idx = 0; idx < 9;idx++)

{

int line = idx % 3;

int column = idx / 3;

c[idx] = 0;

for (int kdx = 0; kdx < 3;kdx++)

{

c[idx] += a[line + kdx * 3] * b[3 * column + kdx];

}

}

a = new double[1000*1000];

a = a.Select((x,idx) => (double)idx).ToArray();

b = new double[1000*1000];

b = b.Select((x,idx) => (double)idx).ToArray();

var resultArr = new double[a.Length];

var watch2 = new System.Diagnostics.Stopwatch();

watch2.Start();

for (int idx = 0; idx < a.Length;idx++)

{

int line = idx % 1000;

int column = idx / 1000;

resultArr[idx] = 0;

for (int kdx = 0; kdx < iterator;kdx++)

{

resultArr[idx] += a[line + kdx * 1000] * b[1000 * column + kdx];

}

}

watch2.Stop();

}

}

}