REAL alpha ~ user_gamma(0.25, 0.5)
REAL tau ~ continuous_uniform(0.5, 10)
INTEGER gamma ~ discrete_uniform(-1, 1)

ENTITY species, "species.data" 
{
    REAL a ~ user_normal(alpha, tau)
    INTEGER waterbird(1)
}

ENTITY cell, "gridcell.data", "neighbours.data"
{
    REAL q = SUM(&x)
    REAL waterpercentage(4)
    INTEGER researchgrade(7)
    INTEGER centeredcoordinate(3)
}

ENTITY observations, "obs.data", combines (cell, species)
{
    REAL p  = EXP(waterbird*a*waterpercentage + gamma*centeredcoordinate + 0.25 * q)/(1 +  EXP(waterbird*a*waterpercentage + gamma*centeredcoordinate + 0.25 * q))
    # 0.25 could be any other constant. defines spatial weighting.

    INTEGER x ~ user_bernoulli(p)
    INTEGER observation(*) ~ user_defined_points2(x, researchgrade)
}