Find interpolated value of light probability

.interpolateLightProb(x, x0, x1, y0, y1)

Arguments

x: the species shade tolerance trait value for which we want to find the interpolated probability.
x0: the floor of x corresponding to a class of shade tolerance in the sufficientLight table.
x1: the ceiling of x corresponding to a class of shade tolerance in the sufficientLight table.
y0: the probability of germination in the sufficientLight table corresponding to x0.
y1: the probability of germination in the sufficientLight table corresponding to x1.

vector of the interpolated value