qml.s_prod

s_prod(scalar, operator, lazy=True, id=None)

Construct an operator which is the scalar product of the given scalar and operator provided.

Parameters

• scalar (float or complex) – the scale factor being multiplied to the operator.

• operator (Operator) – the operator which will get scaled.

Keyword Arguments

• lazy=True (bool) – If lazy=False and the operator is already a scalar product operator, the scalar provided will simply be combined with the existing scaling factor.

• id (str or None) – id for the scalar product operator. Default is None.

Returns

The operator representing the scalar product.

Return type

SProd

Note

This operator supports a batched base, a batched coefficient and a combination of both:

>>> op = qml.s_prod(scalar=4, operator=qml.RX([1, 2, 3], wires=0))
>>> qml.matrix(op).shape
(3, 2, 2)
>>> op = qml.s_prod(scalar=[1, 2, 3], operator=qml.RX(1, wires=0))
>>> qml.matrix(op).shape
(3, 2, 2)
>>> op = qml.s_prod(scalar=[4, 5, 6], operator=qml.RX([1, 2, 3], wires=0))
>>> qml.matrix(op).shape
(3, 2, 2)

But it doesn’t support batching of operators:

>>> op = qml.s_prod(scalar=4, operator=[qml.RX(1, wires=0), qml.RX(2, wires=0)])
AttributeError: 'list' object has no attribute 'batch_size'

See also

SProd and SymbolicOp

Example

>>> sprod_op = s_prod(2.0, qml.X(0))
>>> sprod_op
2.0 * X(0)
>>> sprod_op.matrix()
array([[ 0., 2.],
       [ 2., 0.]])

code/api/pennylane.s_prod

 

Download Python script

 

Download Notebook

 

View on GitHub