class_docstr: Unit tests for clifford compilation function.
class_docstr_tok: ["Unit","tests","for","clifford","compilation","function","."]
docstr: Ensure that given a certain epsilon, the total operator error is below the threshold.
docstr_tok: ["Ensure","that","given","a","certain","epsilon",",","the","total","operator","error","is","below","the","threshold","."]
code: def test_total_error(self, epsilon, circuit):
      """Ensure that given a certain epsilon, the total operator error is below the threshold."""
      dev = qml.device("default.qubit")
  
      qnode_basic = qml.QNode(circuit, dev)
      qnode_transformed = clifford_t_decomposition(
          qnode_basic, epsilon=epsilon, max_depth=10
      )
      mat_exact = qml.matrix(qnode_basic, wire_order=[0, 1])()
      mat_approx = qml.matrix(qnode_transformed, wire_order=[0, 1])()
      phase = qml.math.divide(
          mat_exact,
          mat_approx,
          out=qml.math.zeros_like(mat_exact, dtype=complex),
          where=mat_exact != 0,
      )[qml.math.nonzero(qml.math.round(mat_exact, 10))][0]
      mat_exact /= phase
      diff = mat_exact - mat_approx
      error = qml.math.sqrt(
          qml.math.real(qml.math.trace(qml.math.conj(diff).T @ diff))
          / 2
      )
      assert error < epsilon
  
imports: import math
  from functools import reduce
  import pytest
  import pennylane
  from pennylane.transforms.decompositions.clifford_t_transform import check_clifford_t, clifford_t_decomposition, _rot_decompose, _one_qubit_decompose, _two_qubit_decompose, _CLIFFORD_T_GATES
  from pennylane.transforms.optimization.optimization_utils import _fuse_global_phases
label_desc: Use image node_id 4 for calling the TestCliffordCompile obj's underlying member method code with example usage: obj.test_total_error(epsilon, circuit) without return types