Function validate_densMatrExpecDiagMatrValueIsReal

quest/src/core/validation.cpp:4262–4281

}

void validate_densMatrExpecDiagMatrValueIsReal(qcomp value, qcomp exponent, const char* caller) {

    // this function is only ever called to validate the output of
    // expected value calculations of hermitian diagonal matrices
    // upon density matrices (NOT statevectors) because errors in
    // the latter (due to state unnormalisation, or exponent doma-
    // in, or unintended imaginary components of the diagonal)
    // never damage the real component, which we always safely return

    if (isNumericalValidationDisabled())
        return;

    // precise comparison since non-power overload passes epxonent=1
    string msg = (exponent == qcomp(1,0))?
        report::CALC_DENSMATR_EXPECTED_DIAG_MATR_VALUE_WAS_NOT_APPROX_REAL:
        report::CALC_DENSMATR_EXPECTED_DIAG_MATR_POWER_VALUE_WAS_NOT_APPROX_REAL;

    qreal eps = REDUCTION_EPSILON_FACTOR * global_validationEpsilon;
    assertThat(util_isApproxReal(value, eps), msg, caller);
}