Merge pull request #2 from vmarkovtsev/patch-1

Simplify the chain comparisons

kmc2.pyx

@@ -107,15 +107,10 @@ def kmc2(X, k, chain_length=200, afkmc2=True, random_state=None, weights=None):
             # Markov chain
             for j in range(q_cand.shape[0]):
                 cand_prob = p_cand[j]/q_cand[j]
-                if j == 0 or curr_prob == 0.0:
-                    # Init new chain
+                if j == 0 or curr_prob == 0.0 or cand_prob/curr_prob > rand_a[j]:
+                    # Init new chain             Metropolis-Hastings step
                     curr_ind = j
                     curr_prob = cand_prob
-                else:
-                    # Metropolis-Hastings step
-                    if cand_prob/curr_prob > rand_a[j]:
-                        curr_ind = j
-                        curr_prob = cand_prob
         rel_row = X[cand_ind[curr_ind], :]
         centers[i+1, :] = rel_row.todense().flatten() if sparse else rel_row
     return centers