Algorithm 1: Algorithm to calculate night comparison features. Feature vectors $n_i$ are extracted from nights before a non-migraine day and vectors $m_j$ from nights before a migraine day.

input: Feature vectors $F_{orig}=\{n_1,\dots ,n_a,m_1,\dots ,m_b\}$ output: Night comparison feature matrix F, labels L counter = 1; return feature matrix F, labels L;