tfq.math.fidelity
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Calculate the fidelity between circuits.
@tf.functiontfq.math.fidelity( programs, symbol_names, symbol_values, other_programs )
Compute (potentially many) fidelities between the given circuits and the symbol free comparison circuits.
Calculates out[i][j] as:
\[ |\langle \psi_{ ext{programs[i]} }( ext{symbol_values[i]}) \mid \psi_{ ext{other_programs[j]} } angle|^2 \]
symbols = sympy.symbols('alpha beta')qubits = cirq.GridQubit.rect(1, 2)reference_circuits = [cirq.Circuit((cirq.H**symbols[0]).on_each(qubits)),cirq.Circuit(cirq.X(qubits[0]) ** symbols[0],cirq.Y(qubits[1]) ** symbols[1])]other_circuits = [cirq.Circuit(cirq.X.on_each(qubits)),cirq.Circuit((cirq.Y**0.125).on_each(qubits)),cirq.Circuit((cirq.X**0.5).on_each(qubits))]reference_tensor = tfq.convert_to_tensor(reference_circuits)symbol_tensor = tf.convert_to_tensor([s.name for s in symbols])values_tensor = tf.convert_to_tensor(np.arange(4).reshape(2, 2))other_tensor = tfq.convert_to_tensor([other_circuits, other_circuits])fid = tfq.math.fidelity(reference_tensor, symbol_tensor,values_tensor, other_tensor)fidtf.Tensor([[ 0., 0.925, 0.25],[ 0., 0.036, 0.25]],shape=(2, 3), dtype=float32)
Args | |
|---|---|
programs
|
tf.Tensor of strings with shape [batch_size] containing
the string representations of the circuits
|
symbol_names
|
tf.Tensor of strings with shape [n_params], which
is used to specify the order in which the values in
symbol_values should be placed inside of the circuits in
programs.
|
symbol_values
|
tf.Tensor of real numbers with shape
[batch_size, n_params] specifying parameter values to resolve
into the circuits specificed by programs, following the ordering
dictated by symbol_names.
|
other_programs
|
tf.Tensor of strings with shape [batch_size, n_others]
containing the string representations of the circuits with which to
compute the overlap on programs with. Must not contain any free
symbols.
|
Returns | |
|---|---|
tf.Tensor with shape [batch_size, n_others] where out[i][j] is equal
to the fidelity of programs[i] with symbol_values[i]
resolved in and other_programs[i][j].
|