/// <summary>
/// You might need it to make sure you don't copy
/// your data but recreate a wrapper (if have one)
///
/// O(V)
/// </summary>
public GenTensor <T> Forward()
{
var res = new GenTensor <T>(Shape);
foreach (var index in res.IterateOverElements())
{
res.SetValueNoCheck(ConstantsAndFunctions <T> .Forward(GetValueNoCheck(index)), index);
}
return(res);
}
/// <summary>
/// Creates a vector from an array of primitives
/// Its length will be equal to elements.Length
/// </summary>
public static GenTensor <T> CreateVector(params T[] elements)
{
var res = new GenTensor <T>(elements.Length);
for (int i = 0; i < elements.Length; i++)
{
res.SetValueNoCheck(elements[i], i);
}
return(res);
}
/// <summary>
/// [i, j, k...]th element of the resulting tensor is
/// operation(a[i, j, k...], b[i, j, k...])
/// </summary>
public static GenTensor <T> Zip(GenTensor <T> a,
GenTensor <T> b, Func <T, T, T> operation)
{
#if ALLOW_EXCEPTIONS
if (a.Shape != b.Shape)
{
throw new InvalidShapeException("Arguments should be of the same shape");
}
#endif
var res = new GenTensor <T>(a.Shape);
if (res.Shape.shape.Length == 1)
{
for (int x = 0; x < res.Shape.shape[0]; x++)
{
res.Data[x] = ConstantsAndFunctions <T> .Forward(
operation(a.GetValueNoCheck(x), b.GetValueNoCheck(x)));
}
}
else if (res.Shape.shape.Length == 2)
{
for (int x = 0; x < res.Shape.shape[0]; x++)
{
for (int y = 0; y < res.Shape.shape[1]; y++)
{
res.Data[x * res.Blocks[0] + y] = ConstantsAndFunctions <T> .Forward(
operation(a.GetValueNoCheck(x, y), b.GetValueNoCheck(x, y)));
}
}
}
else if (res.Shape.shape.Length == 3)
{
for (int x = 0; x < res.Shape.shape[0]; x++)
{
for (int y = 0; y < res.Shape.shape[1]; y++)
{
for (int z = 0; z < res.Shape.shape[2]; z++)
{
res.Data[x * res.Blocks[0] + y * res.Blocks[1] + z] = ConstantsAndFunctions <T> .Forward(
operation(a.GetValueNoCheck(x, y, z), b.GetValueNoCheck(x, y, z)));
}
}
}
}
else
{
foreach (var index in res.IterateOverElements())
{
res.SetValueNoCheck(ConstantsAndFunctions <T> .Forward(
operation(a.GetValueNoCheck(index), b.GetValueNoCheck(index))), index);
}
}
return(res);
}
/// <summary>
/// Copies a tensor calling each cell with a .Copy()
///
/// O(V)
/// </summary>
public GenTensor <T> Copy(bool copyElements)
{
var res = new GenTensor <T>(Shape);
if (!copyElements)
{
foreach (var index in res.IterateOverElements())
{
res.SetValueNoCheck(ConstantsAndFunctions <T> .Forward(GetValueNoCheck(index)), index);
}
}
else
{
foreach (var index in res.IterateOverElements())
{
res.SetValueNoCheck(ConstantsAndFunctions <T> .Copy(GetValueNoCheck(index)), index);
}
}
return(res);
}
/// <summary>
/// Creates an indentity matrix whose width and height are equal to diag
/// 1 is achieved with TWrapper.SetOne()
/// 0 is achieved with TWrapper.SetZero()
/// </summary>
public static GenTensor <T> CreateIdentityMatrix(int diag)
{
var res = new GenTensor <T>(diag, diag);
for (int i = 0; i < res.Data.Length; i++)
{
res.Data[i] = ConstantsAndFunctions <T> .CreateZero();
}
for (int i = 0; i < diag; i++)
{
res.SetValueNoCheck(ConstantsAndFunctions <T> .CreateOne, i, i);
}
return(res);
}
/// <summary>
/// Applies scalar product to every vector in a tensor so that
/// you will get a one-reduced dimensional tensor
/// (e. g. TensorVectorDotProduct([4 x 3 x 2], [4 x 3 x 2]) -> [4 x 3]
///
/// O(V)
/// </summary>
public static GenTensor <T> TensorVectorDotProduct(GenTensor <T> a,
GenTensor <T> b)
{
#if ALLOW_EXCEPTIONS
if (a.Shape.SubShape(0, 1) != b.Shape.SubShape(0, 1))
{
throw new InvalidShapeException("Other dimensions of tensors should be equal");
}
#endif
var resTensor = new GenTensor <T>(a.Shape.SubShape(0, 1));
foreach (var index in resTensor.IterateOverElements())
{
var scal = VectorDotProduct(a.GetSubtensor(index), b.GetSubtensor(index));
resTensor.SetValueNoCheck(scal, index);
}
return(resTensor);
}
private static void GetCofactor(GenTensor <T> a, GenTensor <T> temp, int rowId,
int colId, int diagLength)
{
int i = 0, j = 0;
for (int row = 0; row < diagLength; row++)
{
for (int col = 0; col < diagLength; col++)
{
if (row != rowId && col != colId)
{
temp.SetValueNoCheck(a.GetValueNoCheck(row, col), i, j++);
if (j == diagLength - 1)
{
j = 0;
i++;
}
}
}
}
}
