[FEATURE] Add KaNCD (#39)

* add KaNCD model

* delete useless codes in KaNCD.py

* modify default learning rate in KaNCD.py

* add example files for KaNCD

* add doc for KaNCD

* update README.md

* add test files

* delete blank line at the end of file

Author: LegionKing

EduCDM/KaNCD/KaNCD.py

@@ -0,0 +1,164 @@
+# coding: utf-8
+# 2023/7/3 @ WangFei
+
+import logging
+import torch
+import torch.nn as nn
+import torch.optim as optim
+import torch.nn.functional as F
+import numpy as np
+from tqdm import tqdm
+from sklearn.metrics import roc_auc_score, accuracy_score
+from EduCDM import CDM
+
+
+class PosLinear(nn.Linear):
+    def forward(self, input: torch.Tensor) -> torch.Tensor:
+        weight = 2 * F.relu(1 * torch.neg(self.weight)) + self.weight
+        return F.linear(input, weight, self.bias)
+
+
+class Net(nn.Module):
+
+    def __init__(self, exer_n, student_n, knowledge_n, mf_type, dim):
+        self.knowledge_n = knowledge_n
+        self.exer_n = exer_n
+        self.student_n = student_n
+        self.emb_dim = dim
+        self.mf_type = mf_type
+        self.prednet_input_len = self.knowledge_n
+        self.prednet_len1, self.prednet_len2 = 256, 128  # changeable
+
+        super(Net, self).__init__()
+
+        # prediction sub-net
+        self.student_emb = nn.Embedding(self.student_n, self.emb_dim)
+        self.exercise_emb = nn.Embedding(self.exer_n, self.emb_dim)
+        self.knowledge_emb = nn.Parameter(torch.zeros(self.knowledge_n, self.emb_dim))
+        self.e_discrimination = nn.Embedding(self.exer_n, 1)
+        self.prednet_full1 = PosLinear(self.prednet_input_len, self.prednet_len1)
+        self.drop_1 = nn.Dropout(p=0.5)
+        self.prednet_full2 = PosLinear(self.prednet_len1, self.prednet_len2)
+        self.drop_2 = nn.Dropout(p=0.5)
+        self.prednet_full3 = PosLinear(self.prednet_len2, 1)
+
+        if mf_type == 'gmf':
+            self.k_diff_full = nn.Linear(self.emb_dim, 1)
+            self.stat_full = nn.Linear(self.emb_dim, 1)
+        elif mf_type == 'ncf1':
+            self.k_diff_full = nn.Linear(2 * self.emb_dim, 1)
+            self.stat_full = nn.Linear(2 * self.emb_dim, 1)
+        elif mf_type == 'ncf2':
+            self.k_diff_full1 = nn.Linear(2 * self.emb_dim, self.emb_dim)
+            self.k_diff_full2 = nn.Linear(self.emb_dim, 1)
+            self.stat_full1 = nn.Linear(2 * self.emb_dim, self.emb_dim)
+            self.stat_full2 = nn.Linear(self.emb_dim, 1)
+
+        # initialize
+        for name, param in self.named_parameters():
+            if 'weight' in name:
+                nn.init.xavier_normal_(param)
+        nn.init.xavier_normal_(self.knowledge_emb)
+
+    def forward(self, stu_id, input_exercise, input_knowledge_point):
+        # before prednet
+        stu_emb = self.student_emb(stu_id)
+        exer_emb = self.exercise_emb(input_exercise)
+        # get knowledge proficiency
+        batch, dim = stu_emb.size()
+        stu_emb = stu_emb.view(batch, 1, dim).repeat(1, self.knowledge_n, 1)
+        knowledge_emb = self.knowledge_emb.repeat(batch, 1).view(batch, self.knowledge_n, -1)
+        if self.mf_type == 'mf':  # simply inner product
+            stat_emb = torch.sigmoid((stu_emb * knowledge_emb).sum(dim=-1, keepdim=False))  # batch, knowledge_n
+        elif self.mf_type == 'gmf':
+            stat_emb = torch.sigmoid(self.stat_full(stu_emb * knowledge_emb)).view(batch, -1)
+        elif self.mf_type == 'ncf1':
+            stat_emb = torch.sigmoid(self.stat_full(torch.cat((stu_emb, knowledge_emb), dim=-1))).view(batch, -1)
+        elif self.mf_type == 'ncf2':
+            stat_emb = torch.sigmoid(self.stat_full1(torch.cat((stu_emb, knowledge_emb), dim=-1)))
+            stat_emb = torch.sigmoid(self.stat_full2(stat_emb)).view(batch, -1)
+        batch, dim = exer_emb.size()
+        exer_emb = exer_emb.view(batch, 1, dim).repeat(1, self.knowledge_n, 1)
+        if self.mf_type == 'mf':
+            k_difficulty = torch.sigmoid((exer_emb * knowledge_emb).sum(dim=-1, keepdim=False))  # batch, knowledge_n
+        elif self.mf_type == 'gmf':
+            k_difficulty = torch.sigmoid(self.k_diff_full(exer_emb * knowledge_emb)).view(batch, -1)
+        elif self.mf_type == 'ncf1':
+            k_difficulty = torch.sigmoid(self.k_diff_full(torch.cat((exer_emb, knowledge_emb), dim=-1))).view(batch, -1)
+        elif self.mf_type == 'ncf2':
+            k_difficulty = torch.sigmoid(self.k_diff_full1(torch.cat((exer_emb, knowledge_emb), dim=-1)))
+            k_difficulty = torch.sigmoid(self.k_diff_full2(k_difficulty)).view(batch, -1)
+        # get exercise discrimination
+        e_discrimination = torch.sigmoid(self.e_discrimination(input_exercise))
+
+        # prednet
+        input_x = e_discrimination * (stat_emb - k_difficulty) * input_knowledge_point
+        # f = input_x[input_knowledge_point == 1]
+        input_x = self.drop_1(torch.tanh(self.prednet_full1(input_x)))
+        input_x = self.drop_2(torch.tanh(self.prednet_full2(input_x)))
+        output_1 = torch.sigmoid(self.prednet_full3(input_x))
+
+        return output_1.view(-1)
+
+
+class KaNCD(CDM):
+    def __init__(self, **kwargs):
+        super(KaNCD, self).__init__()
+        mf_type = kwargs['mf_type'] if 'mf_type' in kwargs else 'gmf'
+        self.net = Net(kwargs['exer_n'], kwargs['student_n'], kwargs['knowledge_n'], mf_type, kwargs['dim'])
+
+    def train(self, train_set, valid_set, lr=0.002, device='cpu', epoch_n=15):
+        logging.info("traing... (lr={})".format(lr))
+        self.net = self.net.to(device)
+        loss_function = nn.BCELoss()
+        optimizer = optim.Adam(self.net.parameters(), lr=lr)
+        for epoch_i in range(epoch_n):
+            self.net.train()
+            epoch_losses = []
+            batch_count = 0
+            for batch_data in tqdm(train_set, "Epoch %s" % epoch_i):
+                batch_count += 1
+                user_info, item_info, knowledge_emb, y = batch_data
+                user_info: torch.Tensor = user_info.to(device)
+                item_info: torch.Tensor = item_info.to(device)
+                knowledge_emb: torch.Tensor = knowledge_emb.to(device)
+                y: torch.Tensor = y.to(device)
+                pred = self.net(user_info, item_info, knowledge_emb)
+                loss = loss_function(pred, y)
+                optimizer.zero_grad()
+                loss.backward()
+                optimizer.step()
+
+                epoch_losses.append(loss.mean().item())
+
+            print("[Epoch %d] average loss: %.6f" % (epoch_i, float(np.mean(epoch_losses))))
+            logging.info("[Epoch %d] average loss: %.6f" % (epoch_i, float(np.mean(epoch_losses))))
+            auc, acc = self.eval(valid_set, device)
+            print("[Epoch %d] auc: %.6f, acc: %.6f" % (epoch_i, auc, acc))
+            logging.info("[Epoch %d] auc: %.6f, acc: %.6f" % (epoch_i, auc, acc))
+
+        return auc, acc
+
+    def eval(self, test_data, device="cpu"):
+        logging.info('eval ... ')
+        self.net = self.net.to(device)
+        self.net.eval()
+        y_true, y_pred = [], []
+        for batch_data in tqdm(test_data, "Evaluating"):
+            user_id, item_id, knowledge_emb, y = batch_data
+            user_id: torch.Tensor = user_id.to(device)
+            item_id: torch.Tensor = item_id.to(device)
+            knowledge_emb: torch.Tensor = knowledge_emb.to(device)
+            pred = self.net(user_id, item_id, knowledge_emb)
+            y_pred.extend(pred.detach().cpu().tolist())
+            y_true.extend(y.tolist())
+
+        return roc_auc_score(y_true, y_pred), accuracy_score(y_true, np.array(y_pred) >= 0.5)
+
+    def save(self, filepath):
+        torch.save(self.net.state_dict(), filepath)
+        logging.info("save parameters to %s" % filepath)
+
+    def load(self, filepath):
+        self.net.load_state_dict(torch.load(filepath, map_location=lambda s, loc: s))
+        logging.info("load parameters from %s" % filepath)

EduCDM/KaNCD/__init__.py

@@ -0,0 +1,4 @@
+# coding: utf-8
+# 2021/4/1 @ WangFei
+
+from .KaNCD import KaNCD

EduCDM/__init__.py

@@ -9,3 +9,4 @@
 from .NCDM import NCDM
 from .IRT import EMIRT, GDIRT
 from .MIRT import MIRT
+from .KaNCD import KaNCD

README.md

@@ -12,7 +12,7 @@
 [![License](https://img.shields.io/github/license/bigdata-ustc/EduCDM)](LICENSE)
 [![DOI](https://zenodo.org/badge/348569904.svg)](https://zenodo.org/badge/latestdoi/348569904)
 
-The Model Zoo of Cognitive Diagnosis Models, including classic Item Response Ranking (**IRT**), Multidimensional Item Response Ranking (**MIRT**), Deterministic Input, Noisy "And" model(**DINA**), and advanced Fuzzy Cognitive Diagnosis Framework (**FuzzyCDF**), Neural Cognitive Diagnosis Model (**NCDM**), Item Response Ranking framework (**IRR**) and Incremental Cognitive Diagnosis (**ICD**).
+The Model Zoo of Cognitive Diagnosis Models, including classic Item Response Ranking (**IRT**), Multidimensional Item Response Ranking (**MIRT**), Deterministic Input, Noisy "And" model(**DINA**), and advanced Fuzzy Cognitive Diagnosis Framework (**FuzzyCDF**), Neural Cognitive Diagnosis Model (**NCDM**), Item Response Ranking framework (**IRR**), Incremental Cognitive Diagnosis (**ICD**) and Knowledge-association baesd extension of NeuralCD (**KaNCD**).
 
 ## Brief introduction to CDM
 
@@ -38,6 +38,7 @@ More recent researches about CDMs:
 - [NeuralCD](http://staff.ustc.edu.cn/~cheneh/paper_pdf/2020/Fei-Wang-AAAI.pdf): neural cognitive diagnosis framework, a neural-network-based general cognitive diagnosis framework. In this repository we provide the basic implementation NCDM.
 - [IRR](http://home.ustc.edu.cn/~tongsw/files/IRR.pdf): item response ranking framework, a pairwise cognitive diagnosis framework. In this repository we provide the several implementations for most of CDMs.
 - [ICD]: Incremental Cognitive Diagnosis, a framework that tailor cognitive diagnosis into the online scenario of intelligent education. In this repository we provide the several implementations for most of CDMs.
+- [KaNCD](https://ieeexplore.ieee.org/abstract/document/9865139): extended from the NeuralCD framework. We use high-order latent traits of students, exercises and knowledge concepts to capture latent associations among knowledge concepts. 
 
 ## List of models
 
@@ -57,6 +58,7 @@ More recent researches about CDMs:
   * [IRR-DINA](examples/IRR/DINA.ipynb)
   * [IRR-IRT](examples/IRR/IRT.ipynb)
 * [ICD](EduCDM/ICD) [[doc]](docs/ICD.md) 
+* [KaNCD](EduCDM/KaNCD) [[doc\]](docs/KaNCD.md) [[example\]](examples/KaNCD)
 ## Installation
 
 Git and install with `pip`:
@@ -100,3 +102,5 @@ If this repository is helpful for you, please cite our work
 [2] Wang F, Liu Q, Chen E, et al. Neural cognitive diagnosis for intelligent education systems[C]//Proceedings of the AAAI Conference on Artificial Intelligence. 2020, 34(04): 6153-6161.
 
 [3] Tong S, Liu Q, Yu R, et al. Item response ranking for cognitive diagnosis[C]. IJCAI, 2021.
+
+[4] Wang F, Liu Q, Chen E, et al. NeuralCD: A General Framework for Cognitive Diagnosis. IEEE Transactions on Knowledge and Data Engineering (IEEE TKDE), accepted, 2022.

docs/KaNCD.md

@@ -0,0 +1,15 @@
+# KaNCD
+
+The implementation of the KaNCD model in paper: [NeuralCD: A General Framework for Cognitive Diagnosis](https://ieeexplore.ieee.org/abstract/document/9865139)
+
+KaNCD is an **K**nowledge-**a**ssociation based extension of the **N**eural**CD**M (alias NCDM in this package) model. In KaNCD, higher-order low dimensional latent traits of students, exercises and knowledge concepts are used respectively. 
+
+The knowledge difficulty vector of an exercise is calculated from the latent trait of the exercise and the latent trait of each knowledge concept. 
+
+![KDM_MF](F:\git_project\EduCDM\EduCDM\docs\_static\KDM_MF.png)
+
+Similarly, the knowledge proficiency vector of a student is calculated from the latent trait of the student and the latent trait of each knowledge concept.
+
+![KPM_MF](F:\git_project\EduCDM\EduCDM\docs\_static\KPM_MF.png)
+
+Please refer to the paper for more details.