Fix typo/bug in MCMC inversion
`np.rand` should be `np.random.rand`.
@@ -117,7 +117,7 @@ class MCMCInversion(Inversion):
# Test vs. the Metropolis / Hastings criterion
if np.isfinite(dens_new) and\
- np.log(np.rand()) <= min((dens_new - dens, 0.0)):
+ np.log(np.random.rand()) <= min((dens_new - dens, 0.0)):
x = xp
dens = dens_new
acpts = acpts + 1
