fix documentation (#37)

Co-authored-by: Elena Peña Tapia <57907331+ElePT@users.noreply.github.com>

Author: liranszlak

qiskit_addon_opt_mapper/problems/optimization_problem.py

@@ -1201,9 +1201,9 @@ def substitute_variables(
     def to_ising(self) -> tuple[SparsePauliOp, float]:
         """Return the Ising Hamiltonian of this problem.
 
-        Variables are mapped to qubits in the same order, i.e.,
-        i-th variable is mapped to i-th qubit.
-        See https://github.com/Qiskit/qiskit-terra/issues/1148 for details.
+        Variables are mapped to qubits in qiskit order, i.e.,
+        i-th variable is mapped to index n-i in the pauli string, where
+        n is the total number of variables.
 
 
         Returns:

qiskit_addon_opt_mapper/translators/ising.py

@@ -24,9 +24,9 @@
 def to_ising(optimization_problem: OptimizationProblem) -> tuple[SparsePauliOp, float]:
     """Return the Ising Hamiltonian of this problem.
 
-    Variables are mapped to qubits in the same order, i.e.,
-    i-th variable is mapped to i-th qubit.
-    See https://github.com/Qiskit/qiskit-terra/issues/1148 for details.
+    Variables are mapped to qubits in qiskit order, i.e.,
+    i-th variable is mapped to index n-i in the pauli string, where
+    n is the total number of variables.
 
     Args:
         optimization_problem: The problem to be translated.