Diffraction data quality analysis of EVAL15 integration

Linear transformations of variance/covariance matrices

The linear transformation of standard uncertainties involves the full variance/covariance matrix. A method based on the vec operator is described for the case of second-rank tensors, e.g. anisotropic displacement parameters. This method is also applicable for the calculation of equivalent isotropic displacement parameters (U_equiv), the comparison of refinements in different space-group settings and the calculation of standard uncertainties of eigenvalues.

Linear transformations of variance/covariance matrices