def __init__(self, gate, num_controls, num_ancillas_zero,
num_ancillas_dirty):
"""Initialize a multi controlled gate.
Args:
gate (ndarray): 2*2 unitary (given as a (complex) ndarray)
num_controls (int): number of control qubits
num_ancillas_zero (int): number of ancilla qubits that start in the state zero
num_ancillas_dirty (int): number of ancilla qubits that are allowed to start in an
arbitrary state
Raises:
QiskitError: if the input format is wrong; if the array gate is not unitary
"""
self.num_controls = num_controls
self.num_ancillas_zero = num_ancillas_zero
self.num_ancillas_dirty = num_ancillas_dirty
# Check if the gate has the right dimension
if not gate.shape == (2, 2):
raise QiskitError(
"The dimension of the controlled gate is not equal to (2,2).")
# Check if the single-qubit gate is unitary
if not is_isometry(gate, _EPS):
raise QiskitError("The controlled gate is not unitary.")
# Create new gate.
num_qubits = 1 + num_controls + num_ancillas_zero + num_ancillas_dirty
super().__init__("MCGupDiag", num_qubits, [gate])
def __init__(self, isometry, num_ancillas_zero, num_ancillas_dirty):
# Convert to numpy array in case not already an array
isometry = np.array(isometry, dtype=complex)
# change a row vector to a column vector (in the case of state preparation)
if len(isometry.shape) == 1:
isometry = isometry.reshape(isometry.shape[0], 1)
self.num_ancillas_zero = num_ancillas_zero
self.num_ancillas_dirty = num_ancillas_dirty
# Check if the isometry has the right dimension and if the columns are orthonormal
n = np.log2(isometry.shape[0])
m = np.log2(isometry.shape[1])
if not n.is_integer() or n < 0:
raise QiskitError(
"The number of rows of the isometry is not a non negative"
" power of 2.")
if not m.is_integer() or m < 0:
raise QiskitError(
"The number of columns of the isometry is not a non negative"
" power of 2.")
if m > n:
raise QiskitError(
"The input matrix has more columns than rows and hence "
"it can't be an isometry.")
if not is_isometry(isometry, _EPS):
raise QiskitError(
"The input matrix has non orthonormal columns and hence "
"it is not an isometry.")
num_qubits = int(n) + num_ancillas_zero + num_ancillas_dirty
super().__init__("isometry", num_qubits, 0, [isometry])
