nag_real_polygamma (s14aec) Example Program Results x k (d^k/dx^k)psi(x) 1.0 0 -5.7722e-01 0.5 1 4.9348e+00 -3.6 2 -2.2335e+01 8.0 3 4.6992e-03 2.9 4 -1.5897e-01 -4.7 5 1.6566e+05 -5.4 6 4.1378e+05