Contains analysis code used in the paper: Halpin SJ, Xing L, Greenwood DC, Tang NKY, Trujillo-Barreto N, Brown C, Jones AKP, O'Connor RJ, Casson AJ, Sivan M, "Pre-sleep alpha brain entrainment by audio or visual stimulation for fibromyalgia and sleep disturbance: A randomised crossover feasibility trial".