conditionLatentObs assigns q_y(i) vs q_z(i) following Section 5.1
in Katzfuss and Guinness (2018). This function only needs to be run once
per SGV analysis.
conditionLatentObs(nID, coords_ord, N)A matrix indicating whether the conditioning set for each location
is on the latent process (y, 1) or the observed values (z, 0).
N x k matrix of neighbor indices.
N x 2 matrix of locations.
Scalar; number of locations (observed only!).