Cosmic shear setup with the six KiDS-Legacy tomographic bins. The colour bar shows the tomographic bin index combination, I (i.e. for tomographic bins i, j the index is $I=\sum _{\alpha }^i\sum _{\beta =\alpha }^j$). Left: comparison between the OneCovariance code and ccl. The relative difference between the angular power spectrum calculation is shown as a percentage. Matter power spectra have been modelled using the Takahashi et al. (2012) version of the halo model. Right: relative difference in per cent between the diagonal elements of the covariance matrix for ξ_± calculated with the KiDS-1000 covariance code (Joachimi et al. 2021) and the OneCovariance code. The covariance shown here does not contain shape noise.