public static Tensor <Type> Create(Tensor <Type>[] inputs, Scalar <Type> .Var[] vars, Scalar <Type> abstraction)
{
if (inputs.Length != vars.Length)
{
throw new ArgumentException("Need one captured by inputs");
}
var shape = GetShape(inputs);
// guw: the following code aims at simplifying abstraction like (_x, _y) => _x
// for now I haven't see a case where this happens, but it might in the future
#if NOT_USED
var varsInAbstraction = abstraction.FindAll <Scalar <Type> .Var>();
// easy case, everybody is to be removed
if (varsInAbstraction.Count == 0)
{
return(Op.Const(abstraction, shape));
}
var varsToRemove = vars.Where(v => !varsInAbstraction.Contains(v)).ToList();
if (varsToRemove.Count > 0)
{
inputs = inputs.Where((_, i) => !varsToRemove.Contains(vars[i])).ToArray();
vars = vars.Where(v => !varsToRemove.Contains(v)).ToArray();
}
if (inputs.Length == 0)
{
return(Op.Const(abstraction, shape));
}
#endif
// As `Deindexing` operations are heavy we try to apply the lambda before deindexing.
var deindexing = inputs.All(x => x is Deindexing <Type>);
if (deindexing)
{
var indices = (inputs.First() as Deindexing <Type>).Indices;
var deindexedShape = inputs.First().Shape;
if (inputs.All(x => (x as Deindexing <Type>).Indices == indices && x.Shape.WillEqualTo(deindexedShape)))
{
// TODO not covered
var nary = Create(
inputs.Select(x => (x as Deindexing <Type>).Content).ToArray(),
vars,
abstraction
);
return(Deindexing <Type> .Create(nary, deindexedShape, indices));
}
}
return(new Elementwise(inputs, vars, abstraction, shape));
}
public static Tensor <Type> operator -(Tensor <Type> x)
{
switch (x)
{
case Elementwise unary when unary.Abstraction is Scalars.Neg <Type> :
return(unary.Inputs[0]); // -(-x) = x
case Elementwise binary when binary.Abstraction is Scalars.Sub <Type> :
return(binary.Inputs[1] - binary.Inputs[0]); // -(x - y) = y - x
case Fill <Type> fill:
return(Op.Const(-fill.x, fill.Shape));
case OneHot <Type> oneHot:
return(Op.OneHot(oneHot.Shape, oneHot.Index, -oneHot.Content));
default:
return(Op.Apply(x, _x => - _x));
}
}
