negative sampling by choosing from other user's items

main.py

@@ -24,7 +24,7 @@ def get_params():
     args.add_argument("-m", "--margin", default=1, type=float)
     args.add_argument("-p", "--dropout_p", default=0.5, type=float)
 
-    args.add_argument("-gpu", "--device", default=0, type=int)
+    args.add_argument("-gpu", "--device", default=1, type=int)
 
 
     args = args.parse_args()

sampler.py

@@ -7,11 +7,19 @@ from collections import defaultdict, Counter
 from multiprocessing import Process, Queue
 
 
-def random_neq(l, r, s):
-    t = np.random.randint(l, r)
-    while t in s:
-        t = np.random.randint(l, r)
-    return t
+def random_neq(l, r, s, user_train,usernum):
+    # t = np.random.randint(l, r)
+    # while t in s:
+    #     t = np.random.randint(l, r)
+    # return t
+    user = np.random.randint(1, usernum + 1)
+    candid_item = user_train[user][np.random.randint(0,len(user_train[user]))]
+
+    while candid_item in s:
+        user = np.random.randint(1, usernum + 1)
+        candid_item = user_train[user][np.random.randint(0, len(user_train[user]))]
+    return candid_item
+
 
 def sample_function_mixed(user_train, usernum, itemnum, batch_size, maxlen, result_queue, SEED):
     def sample():
@@ -37,16 +45,20 @@ def sample_function_mixed(user_train, usernum, itemnum, batch_size, maxlen, resu
             for i in reversed(user_train[user][min(0, nxt_idx - 1 - maxlen) : nxt_idx - 1]):
                 seq[idx] = i
                 pos[idx] = nxt
-                if nxt != 0: neg[idx] = random_neq(1, itemnum + 1, ts)
+                if nxt != 0: neg[idx] = random_neq(1, itemnum + 1, ts, user_train,usernum)
                 nxt = i
                 idx -= 1
                 if idx == -1: break
 
+            # for i in range(len(neg)):
+            #     neg[i] = random_neq(1, itemnum + 1, ts, user_train,usernum)
+
             curr_rel = user
             support_triples, support_negative_triples, query_triples, negative_triples = [], [], [], []
             for idx in range(maxlen-1):
                 support_triples.append([seq[idx],curr_rel,pos[idx]])
-                support_negative_triples.append([seq[idx],curr_rel,neg[idx]])
+                # support_negative_triples.append([seq[idx],curr_rel,neg[idx]])
+                support_negative_triples.append([seq[-1], curr_rel, neg[idx]])
             query_triples.append([seq[-1],curr_rel,pos[-1]])
             negative_triples.append([seq[-1],curr_rel,neg[-1]])
 

utils.py

@@ -5,12 +5,22 @@ import random
 import numpy as np
 from collections import defaultdict, Counter
 from multiprocessing import Process, Queue
+
 # sampler for batch generation
-def random_neq(l, r, s):
-    t = np.random.randint(l, r)
-    while t in s:
-        t = np.random.randint(l, r)
-    return t
+def random_neq(l, r, s,user_train):
+    # t = np.random.randint(l, r)
+    # while t in s:
+    #     t = np.random.randint(l, r)
+    # return t
+
+    user = random.choice(list(user_train.keys()))
+    item = random.choice(user_train[user])
+
+    while item in s:
+        user = random.choice(list(user_train.keys()))
+        item = random.choice(user_train[user])
+    return item
+
 
 def trans_to_cuda(variable):
     if torch.cuda.is_available():
@@ -97,6 +107,7 @@ class DataLoader(object):
         
         self.itemnum = itemnum
 
+
     def next_one_on_eval(self):
         if self.curr_tri_idx == self.num_tris:
             return "EOT", "EOT"
@@ -116,7 +127,7 @@ class DataLoader(object):
             seq[idx] = i
             if idx > 0:
                 pos[idx - 1] = i
-                if i != 0: neg[idx - 1] = random_neq(1, self.itemnum + 1, ts)
+                if i != 0: neg[idx - 1] = random_neq(1, self.itemnum + 1, ts,self.train)
             idx -= 1
             if idx == -1: break
 
@@ -124,7 +135,8 @@ class DataLoader(object):
         support_triples, support_negative_triples, query_triples, negative_triples = [], [], [], []
         for idx in range(self.maxlen-1):
             support_triples.append([seq[idx],curr_rel,pos[idx]])
-            support_negative_triples.append([seq[idx],curr_rel,neg[idx]])
+            # support_negative_triples.append([seq[idx],curr_rel,neg[idx]])
+            support_negative_triples.append([seq[-1],curr_rel,neg[idx]])
 
         rated = ts
         rated.add(0)