src/syntha/generator/mixed_corr.py implements Olsson 1982 polyserial + Bonett & Price tetrachoric with the Drezner 1978 BVN CDF approximation. We need a side-by-side validation against R's polycor::polyserial / polychor on, say, 500 simulated 2-column datasets across a grid of (true_rho, sample_size, p_binary). Acceptance: max abs diff < 0.02 for n>=1000.
src/syntha/generator/mixed_corr.py implements Olsson 1982 polyserial + Bonett & Price tetrachoric with the Drezner 1978 BVN CDF approximation. We need a side-by-side validation against R's polycor::polyserial / polychor on, say, 500 simulated 2-column datasets across a grid of (true_rho, sample_size, p_binary). Acceptance: max abs diff < 0.02 for n>=1000.