# Direct Fidelity Estimation¶

Direct fidelity estimation (DFE) uses knowledge about the ideal target state or process to perform a tailored set of measurements to quickly certify a quantum state or a quantum process at lower cost than full tomography.

 do_dfe(qc, benchmarker, program, qubits, …) A wrapper around experiment generation, data acquisition, and estimation that runs a DFE experiment and returns the (fidelity, std_err) pair along with the experiment and results.

## State DFE¶

 generate_exhaustive_state_dfe_experiment(…) Estimate state fidelity by exhaustive direct fidelity estimation. generate_monte_carlo_state_dfe_experiment(…) Estimate state fidelity by sampled direct fidelity estimation.

## Process DFE¶

 generate_exhaustive_process_dfe_experiment(…) Estimate process fidelity by exhaustive direct fidelity estimation (DFE). generate_monte_carlo_process_dfe_experiment(…) Estimate process fidelity by randomly sampled direct fidelity estimation.

## Data Acquisition¶

 acquire_dfe_data(qc, expt, num_shots, …) Acquire data necessary for direct fidelity estimate (DFE).

## Analysis¶

 estimate_dfe(results, kind) Analyse data from experiments to obtain a direct fidelity estimate (DFE).