Bug in Real ITensor::operator()

[BapRoyer]

I think there is a scale_.real()* missing in the case that the tensor is diagonal.

Real ITensor::
operator()(const IndexVal& iv1, const IndexVal& iv2) const
    {
    ITENSOR_CHECK_NULL
    if(type_ == Diag)
        {
        if(iv1.i != iv2.i) return 0;
        return r_->v.at(iv1.i-1);
        }
    return scale_.real()*r_->v[_ind2(iv1,iv2)];
    }

[emstoudenmire]

Thanks for pointing this out! In the new version coming out soon, all storage types (Dense, Diag, etc.) and versions of operator() taking different numbers of IndexVals all share the same (templated) element access code, so bugs like this will be much less likely to happen.