// result = a + alpha * b
public static Array <Real> Add(this Array <Real> a, Array <Real> b, Real alpha = 1, Array <Real> result = null)
{
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
if (alpha == 1 && incx == 1 && incy == 1 && incz == 1)
{
Blas.vadd(n, x, offsetx, y, offsety, z, offsetz);
}
else if (alpha == -1 && incx == 1 && incy == 1 && incz == 1)
{
Blas.vsub(n, x, offsetx, y, offsety, z, offsetz);
}
else if (z == x)
{
Blas.axpy(n, alpha, y, offsety, incy, x, offsetx, incx);
}
else if (z == y && alpha == 1)
{
Blas.axpy(n, alpha, x, offsetx, incx, y, offsety, incy);
}
// TODO: else if (incx == 0) => broadcast x ??
// TODO: else if (incy == 0) => broadcast y ??
else
{
for (int i = 0; i < n; i++) // TODO: Blas.copy y => x, Blas.axpy(1, x, y)
{
z[offsetz] = x[offsetx] + alpha * y[offsety];
offsetx += incx;
offsety += incy;
offsetz += incz;
}
} // See also: mkl_?omatadd => C := alpha*op(A) + beta*op(B)
}));
}
public static Array <Real> Mul(this Array <Real> a, Array <Real> b, Array <Real> result = null)
{
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
if (incx == 1 && incy == 1 && incz == 1)
{
Blas.vmul(n, x, offsetx, y, offsety, z, offsetz);
}
else if (incx == 0) // x[offsetx] is broadcast: y[:] * x[offsetx]
{
Blas.gemv(Order.RowMajor, Transpose.NoTrans, n, 1, 1, y, offsety, incy, x, offsetx, 1, 0, z, offsetz, incz);
}
//else if (incy == 0) // y[offsety] is broadcast: x[:] * y[offsety]
// Blas.gemv(Order.RowMajor, Transpose.NoTrans, n, 1, 1, x, offsetx, incx, y, offsety, 1, 0, z, offsetz, incz);
else // when everything else fails, fallback to slow version
{
for (int i = 0; i < n; i++)
{
z[offsetz] = x[offsetx] * y[offsety];
offsetx += incx;
offsety += incy;
offsetz += incz;
}
}
}));
}
public static Array <Real> Add(this Array <Real> a, Real b, Real alpha = 1, Array <Real> result = null)
{
if (result == null)
{
result = new Array <Real>(a.Shape);
}
Array_.ElementwiseOp(a, result,
(n, x, offsetx, incx, z, offsetz, incz) =>
{
if (z == x)
{
Blas.axpy(n, alpha, ref b, x, offsetx, incx);
}
else
{
for (int i = 0; i < n; i++)
{
z[offsetz] = x[offsetx] + alpha * b;
offsetx += incx;
offsetz += incz;
}
}
});
return(result);
}
public static Array <Real> Sum(this Array <Real> a, int axis, Func <Real, Real> f, Array <Real> result = null, bool keepDims = false)
{
if (axis < 0)
{
axis = a.Shape.Length + axis;
}
result = result == null?NN.Zeros <Real>(GetAggregatorResultShape(a, axis, true)) : result.Clear();
var slice = a.Slices(); // TODO: create a new ElementwiseOp
int ndim = a.Shape[axis];
for (int d = 0; d < ndim; ++d)
{
slice[axis] = (d, d + 1);
Array_.ElementwiseOp(a[slice], result, (n, _a, off_a, step_a, _r, off_r, step_r) => {
Real s = 0;
for (int i = 0; i < n; i++)
{
s += f(_a[off_a]);
off_a += step_a;
off_r += step_r;
}
result += s;
});
}
if (!keepDims)
{
result = result.Reshape(RemoveAxis(result.Shape, axis));
}
return(result);
}
/// <summary><a href="http://docs.scipy.org/doc/numpy/reference/generated/numpy.argmax.html">see NumPy doc</a></summary>
public static Array <int> Argmax(this Array <Real> a, int axis, bool keepDims = false, Array <int> result = null)
{
if (axis < 0)
{
axis = a.Shape.Length + axis;
}
if (result == null)
{
result = NN.Zeros <int>(GetAggregatorResultShape(a, axis, true));
}
else if (result.NDim != a.NDim)
{
result = result.Reshape(GetAggregatorResultShape(a, axis, true));
}
Array_.ElementwiseOp(a, result, (n, x, offx, incx, y, offy, incy) =>
{
var max = x[offx]; offx += incx;
var argmax = 0;
for (int i = 1; i < n; ++i)
{
var value = x[offx];
if (value > max)
{
max = value;
argmax = i;
}
offx += incx;
}
y[offy] = argmax;
}, axis);
return(keepDims ? result : result.Reshape(GetAggregatorResultShape(a, axis, false)));
}
public static Array <Real> Scale(this Array <Real> a, Real alpha, Array <Real> result = null)
{
if (result != a)
{
result = a.Copy(result: result);
}
Array_.ElementwiseOp(0, result, 0, (n, x, offsetx, incx) => { Blas.scal(n, alpha, x, offsetx, incx); });
return(result);
}
/// <summary>a += α * b </summary>
public static void Acc(this Array <Real> a, Array <Real> b, Real alpha = 1)
{
if (alpha == 0)
{
return;
}
b.AssertOfShape(a.Shape);
Array_.ElementwiseOp(b, a, (n, x, offsetx, incx, y, offsety, incy) =>
{
// TODO: broadcasting ?
Blas.axpy(n, alpha, x, offsetx, incx, y, offsety, incy);
});
}
public static Array <Int> Apply(this Array <Int> a, Array <Int> b, Func <Int, Int, Int> fn, Array <Int> result = null)
{
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
for (int i = 0; i < n; i++)
{
z[offsetz] = fn(x[offsetx], y[offsety]);
offsetx += incx;
offsety += incy;
offsetz += incz;
}
}));
}
public static Array <Int> Div(this Array <Int> a, Array <Int> b, Array <Int> result = null)
{
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
for (int i = 0; i < n; i++)
{
z[offsetz] = x[offsetx] / y[offsety];
offsetx += incx;
offsety += incy;
offsetz += incz;
}
}));
}
public static Array <Int> Acc(this Array <Int> a, Array <Int> b, Int alpha = 1)
{
Array_.ElementwiseOp(a, b,
(n, x, offsetx, incx, y, offsety, incy) =>
{
for (int i = 0; i < n; i++)
{
x[offsetx] += alpha * y[offsety];
offsetx += incx;
offsety += incy;
}
});
return(a);
}
public static Array <Real> NotEqual(this Array <Real> a, Array <Real> b, Array <Real> result = null)
{
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
for (int i = 0; i < n; i++)
{
z[offsetz] = x[offsetx] != y[offsety] ? 1 : 0;
offsetx += incx;
offsety += incy;
offsetz += incz;
}
}));
}
public static Array <Real> Copy(this Array <Real> a, Array <Real> result = null)
{
if (a == result)
{
return(result);
}
if (result == null)
{
result = new Array <Real>(a.Shape);
}
Array_.ElementwiseOp(result, a, (n, x, offsetx, incx, y, offsety, incy) =>
{
Blas.copy(n, y, offsety, incy, x, offsetx, incx);
});
return(result);
}
public static Int Min(this Array <Int> a)
{
Int result = Int.MaxValue;
Array_.ElementwiseOp(0, a, 0,
(n, x, offsetx, incx) =>
{
Int s = Int.MaxValue;
for (int i = 0; i < n; i++)
{
s = Math.Min(s, x[offsetx]);
offsetx += incx;
}
result = Math.Min(result, s);
});
return(result);
}
public static Real Sum(this Array <Real> a)
{
Real result = 0;
Array_.ElementwiseOp(0, a, 0,
(n, x, offsetx, incx) =>
{
Real s = 0;
for (int i = 0; i < n; i++)
{
s += x[offsetx];
offsetx += incx;
}
result += s;
});
return(result);
}
public static Array <Int> Apply(this Array <Int> a, Func <Int, Int> fn, Array <Int> result = null)
{
if (result == null)
{
result = new Array <Int>(a.Shape);
}
Array_.ElementwiseOp(a, result, (n, x, offsetx, incx, y, offsety, incy) =>
{
for (int i = 0; i < n; i++)
{
y[offsety] = fn(x[offsetx]);
offsetx += incx;
offsety += incy;
}
});
return(result);
}
public static Real Min(this Array <Real> a)
{
Real result = Real.PositiveInfinity;
Array_.ElementwiseOp(0, a, 0,
(n, x, offsetx, incx) =>
{
Real s = Real.PositiveInfinity;
for (int i = 0; i < n; i++)
{
s = Math.Min(s, x[offsetx]);
offsetx += incx;
}
result = Math.Min(result, s);
});
return(result);
}
public static Array <Real> Equal(this Array <Real> a, Real b, Array <Real> result = null)
{
if (result == null)
{
result = new Array <Real>(a.Shape);
}
Array_.ElementwiseOp(a, result,
(n, x, offsetx, incx, z, offsetz, incz) =>
{
for (int i = 0; i < n; i++)
{
z[offsetz] = x[offsetx] == b ? 1 : 0;
offsetx += incx;
offsetz += incz;
}
});
return(result);
}
public static Array <Int> Copy(this Array <Int> a, Array <Int> result = null)
{
if (result == null)
{
result = new Array <Int>(a.Shape);
}
Array_.ElementwiseOp(result, a, (n, x, offsetx, incx, y, offsety, incy) =>
{
//Blas.copy(n, y, offsety, incy, x, offsetx, incx);
for (int i = 0; i < n; i++)
{
x[offsetx] = y[offsety];
offsetx += incx;
offsety += incy;
}
});
return(result);
}
// result = a + alpha * b
public static Array <Int> Add(this Array <Int> a, Array <Int> b, Int alpha = 1, Array <Int> result = null)
{
if (result == a)
{
return(a.Acc(b, alpha));
}
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
for (int i = 0; i < n; i++)
{
z[offsetz] = x[offsetx] + alpha * y[offsety];
offsetx += incx;
offsety += incy;
offsetz += incz;
}
}));
}
public static int Argmin(this Array <Real> a)
{
Real min = Real.PositiveInfinity;
int pos = -1;
Array_.ElementwiseOp(0, a, 0,
(n, x, offsetx, incx) =>
{
for (int i = 0; i < n; i++)
{
if (x[offsetx] < min)
{
min = x[offsetx];
pos = offsetx;
}
offsetx += incx;
}
});
return(pos);
}
public static int Argmax(this Array <Int> a, int[] result = null)
{
Int min = Int.MinValue;
int pos = -1;
Array_.ElementwiseOp(0, a, 0,
(n, x, offsetx, incx) =>
{
for (int i = 0; i < n; i++)
{
if (x[offsetx] > min)
{
min = x[offsetx];
pos = offsetx;
}
offsetx += incx;
}
});
return(pos);
}
public static int[] ArgMin(this Array <Int> a, int[] result = null)
{
Int min = Int.MaxValue;
int pos = -1;
Array_.ElementwiseOp(0, a, 0,
(n, x, offsetx, incx) =>
{
for (int i = 0; i < n;
i++)
{
if (x[offsetx] < min)
{
min = x[offsetx];
pos = offsetx;
}
offsetx += incx;
}
});
return(a.UnravelIndex(pos, result));
}
public static Array <Real> Div(this Array <Real> a, Array <Real> b, Array <Real> result = null)
{
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
if (incx == 1 && incy == 1 && incz == 1)
{
Blas.vdiv(n, x, offsetx, y, offsety, z, offsetz);
}
// TODO: else if (incx == 0) dgemv 1/x
// TODO: else if (incy == 0) dgemv 1/y
else
{
for (int i = 0; i < n; i++)
{
z[offsetz] = x[offsetx] / y[offsety];
offsetx += incx;
offsety += incy;
offsetz += incz;
}
}
}));
}