The Hyper CP experiment measured the asymmetry parameter in the decay Ξ−→Λ0π− and the charge conjugate mode, in practice this is a fit to a normalised distribution 12(1+αcosθ). The paper only gives the number for the α parameter and not the distribution, so the distribution is calculated. The α parameter is then extracted using a χ2 fit. This analysis is useful for testing spin correlations in hadron decays.