Environment

• Qiskit version: All versions
• Python version: All versions
• Operating system: All operating systems

What is happening?

When converting a QuantumState (or Statevector) to a dictionary, the _vector_to_dict function accepts an optional "decimals" parameter which should round the values to a given number of decimals.

While it is calculated, in the case where string_labels are present, the return result pulls the unrounded values.

How can we reproduce the issue?

from qiskit import QuantumCircuit, qasm3
from qiskit.quantum_info import Statevector
from qiskit import quantum_info as qi

def run_file(filename):
    qc = qasm3.load(filename)
    qc.remove_final_measurements()
    sv = qi.Statevector(qc)
    print(f"{sv.to_dict(decimals=3)}")```

What should happen?

The to_dict(decimals=3) should return the results rounded to 3 decimal places

Any suggestions?

At the end of _vector_to_dict, the item of vec[inds] should be changed to vals[inds], see below:

        # Make dict of tuples
        if string_labels:
            return dict(zip(kets, **vals**[inds]))

        return {tuple(ket): val for ket, val in zip(kets, vals[inds])}