  Despite being known for a long time the anomalous Hall effect still attracts
attention because of its complex origins, its connection to topology and
because it serves as a useful probe of the magnetic order. Here we study the
anomalous Hall effect using automatic high-throughput calculation scheme. We
calculate the intrinsic anomalous Hall effect in 2871 ferromagnetic materials.
We use these results to study general properties of the anomalous Hall effect
such as its dependence on the strength of the spin-orbit coupling or
magnetization. We also examine the origin of the anomalous Hall effect in the
materials with the largest effect and show that the origin of the large
anomalous Hall effect is usually associated with symmetry protected band
degeneracies in the non-relativistic electronic structure, typically mirror
symmetry protected nodal lines. Additionally, we study the dependence of the
anomalous Hall effect on the magnetization direction, showing that in many
materials it differs significantly from the commonly assumed expression
$\mathbf{j}^\text{AHE} \sim \mathbf{M} \times \mathbf{E}$.
