pytorch-frame 0.1.0

Tabular Deep Learning Library for PyTorch

A modular deep learning framework for building neural network models on heterogeneous tabular data.

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Documentation

PyTorch Frame is a deep learning extension for PyTorch, designed for heterogeneous tabular data with different column types, including numerical, categorical, time, text, and images. It offers a modular framework for implementing existing and future methods. The library features methods from state-of-the-art models, user-friendly mini-batch loaders, benchmark datasets, and interfaces for custom data integration.

PyTorch Frame democratizes deep learning research for tabular data, catering to both novices and experts alike. Our goals are:

1. Facilitate Deep Learning for Tabular Data: Historically, tree-based models (e.g., XGBoost) excelled at tabular learning but had notable limitations, such as integration difficulties with downstream models such as GNNs, and handling complex column types (e.g., text, sequences, images). Deep tabular models are promising to resolve the limitations.

2. Expand Functionalities and Model Architectures: We are enhancing PyTorch Frame to handle diverse column types, like time images, language, and sequences, and integrate cutting-edge technologies like large language models.

• Library Highlights
• Architecture Overview
• Quick Tour
• Implemented Deep Tabular Models
• Benchmark
• Installation

Library Highlights

PyTorch Frame builds directly upon PyTorch, ensuring a smooth transition for existing PyTorch users. Key features include:

• Diverse column types: Supports learning across various column types like categorical, numberical, and texts. Future plans encompass sequences, multicategories, images, and time.
• Modular model design: Enables modular deep learning model implementations, promoting reusability, clear coding, and experimentation flexibility. Further details in the architecture overview.
• Models Implements many state-of-the-art deep tabular models as well as strong GBDTs (XGBoost and CatBoost) with hyper-parameter tuning.
• Datasets: Comes with a collection of readily-usable tabular datasets. Also supports custom datasets to solve your own problem. We benchmark deep tabular models against GBDTs.
• Pytorch integration: Integrates effortlessly with other PyTorch libraries, like PyG, facilitating end-to-end training of PyTorch Frame with downstream PyTorch models.

Architecture Overview

Models in PyTorch Frame follow a modular design of FeatureEncoder, TableConv, and Decoder, as shown in the figure below:

In essence, this modular setup empowers users to effortlessly experiment with myriad architectures:

• Materialization handles converting the raw pandas DataFrame into a TensorFrame that is amenable to Pytorch-based training and modeling.
• FeatureEncoder encodes TensorFrame into hidden column embeddings of size [batch_size, num_cols, channels].
• TableConv models column-wise interactions over the hidden embeddings.
• Decoder generates embedding/prediction per row.

Quick Tour

In this quick tour, we showcase the ease of creating and training a deep tabular model with only a few lines of code.

Build your own deep tabular model

In the first example, we implement a simple ExampleTransformer following the modular architecture of Pytorch Frame. A model maps TensorFrame into embeddings. We decompose ExampleTransformer, and most other models in Pytorch Frame into three modular components.

• self.encoder: The encoder maps an input TensorFrame to an embedding of size [batch_size, num_cols, channels]. To handle input of different column types, we use StypeWiseFeatureEncoder where users can specify different encoders using a dictionary. In this example, we use EmbeddingEncoder for categorical features and LinearEncoder for numerical features--they are both built-in encoders in Pytorch Frame.
• self.convs: We create a two layers of TabTransformerConv. Each TabTransformerConv module transforms an embedding of size [batch_size, num_cols, channels] and into an embedding of the same size.
• self.decoder: We use a mean-based decoder that maps the dimension of the embedding back from [batch_size, num_cols, channels] to [batch_size, out_channels].

from typing import Any, Dict, List

from torch import Tensor
from torch.nn import Linear, Module, ModuleList

import torch_frame
from torch_frame import TensorFrame, stype
from torch_frame.data.stats import StatType
from torch_frame.nn.conv import TabTransformerConv
from torch_frame.nn.encoder import (
    EmbeddingEncoder,
    LinearEncoder,
    StypeWiseFeatureEncoder,
)


class ExampleTransformer(Module):
    def __init__(
        self,
        channels: int,
        out_channels: int,
        num_layers: int,
        num_heads: int,
        col_stats: Dict[str, Dict[StatType, Any]],
        col_names_dict: Dict[torch_frame.stype, List[str]],
    ):
        super().__init__()
        self.encoder = StypeWiseFeatureEncoder(
            out_channels=channels,
            col_stats=col_stats,
            col_names_dict=col_names_dict,
            stype_encoder_dict={
                stype.categorical: EmbeddingEncoder(),
                stype.numerical: LinearEncoder()
            },
        )
        self.tab_transformer_convs = ModuleList([
            TabTransformerConv(
                channels=channels,
                num_heads=num_heads,
            ) for _ in range(num_layers)
        ])
        self.decoder = Linear(channels, out_channels)

    def forward(self, tf: TensorFrame) -> Tensor:
        x, _ = self.encoder(tf)
        for tab_transformer_conv in self.tab_transformer_convs:
            x = tab_transformer_conv(x)
        out = self.decoder(x.mean(dim=1))
        return out

Once we decide the model, we can load the Adult Census Income dataset and create a train dataloader.

    from torch_frame.datasets import Yandex

    dataset = Yandex(root='/tmp/adult', name='adult')
    dataset.materialize()
    train_dataset = dataset[:0.8]
    train_loader = DataLoader(train_dataset.tensor_frame, batch_size=128,
                            shuffle=True)

We can now optimize the model in a training loop, similar to the standard PyTorch training procedure.

import torch
import torch.nn.functional as F
from tqdm import tqdm

device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
model = ExampleTransformer(
    channels=32,
    out_channels=dataset.num_classes,
    num_layers=2,
    num_heads=8,
    col_stats=train_dataset.col_stats,
    col_names_dict=train_dataset.tensor_frame.col_names_dict,
).to(device)

optimizer = torch.optim.Adam(model.parameters())

for epoch in range(50):
    for tf in tqdm(train_loader):
        pred = model.forward(tf)
        loss = F.cross_entropy(pred, tf.y)
        optimizer.zero_grad()
        loss.backward()

Implemented Deep Tabular Models

We list currently supported deep tabular models:

• Trompt from Chen et al.: Trompt: Towards a Better Deep Neural Network for Tabular Data (ICML 2023) [Example]
• FTTransformer from Gorishniy et al.: Revisiting Deep Learning Models for Tabular Data (NeurIPS 2021) [Example]
• ResNet from Gorishniy et al.: Revisiting Deep Learning Models for Tabular Data (NeurIPS 2021) [Example]
• TabNet from Arık et al.: TabNet: Attentive Interpretable Tabular Learning (AAAI 2021) [Example]
• ExcelFormer from Chen et al.: ExcelFormer: A Neural Network Surpassing GBDTs on Tabular Data [Example]
• TabTransformer from Huang et al.: TabTransformer: Tabular Data Modeling Using Contextual Embeddings [Example]

In addition, we implemented XGBoost and CatBoost examples with hyperparameter-tuning using Optuna for users who'd like to compare their model performance with GBDTs.

Benchmark

We benchmark recent tabular deep learning models against GBDTs over diverse public datasets with different sizes and task types.

The following chart shows the performance of various deep learning models on small regression datasets, where the row represents the model names and the column represents dataset indices (we have 13 datasets here). For more results on classification and larger datasets, please check the benchmark documentation.

	dataset_0	dataset_1	dataset_2	dataset_3	dataset_4	dataset_5	dataset_6	dataset_7	dataset_8	dataset_9	dataset_10	dataset_11	dataset_12
XGBoost	0.247±0.000	0.077±0.000	0.167±0.000	1.119±0.000	0.328±0.000	1.024±0.000	0.292±0.000	0.606±0.000	0.876±0.000	0.023±0.000	0.697±0.000	0.865±0.000	0.435±0.000
CatBoost	0.265±0.000	0.062±0.000	0.128±0.000	0.336±0.000	0.346±0.000	0.443±0.000	0.375±0.000	0.273±0.000	0.881±0.000	0.040±0.000	0.756±0.000	0.876±0.000	0.439±0.000
Trompt	0.261±0.003	0.015±0.005	0.118±0.001	0.262±0.001	0.323±0.001	0.418±0.003	0.329±0.009	0.312±0.002	OOM	0.008±0.001	0.779±0.006	0.874±0.004	0.424±0.005
ResNet	0.288±0.006	0.018±0.003	0.124±0.001	0.268±0.001	0.335±0.001	0.434±0.004	0.325±0.012	0.324±0.004	0.895±0.005	0.036±0.002	0.794±0.006	0.875±0.004	0.468±0.004
FTTransformerBucket	0.325±0.008	0.096±0.005	0.360±0.354	0.284±0.005	0.342±0.004	0.441±0.003	0.345±0.007	0.339±0.003	OOM	0.105±0.011	0.807±0.010	0.885±0.008	0.468±0.006
ExcelFormer	0.302±0.003	0.099±0.003	0.145±0.003	0.382±0.011	0.344±0.002	0.411±0.005	0.359±0.016	0.336±0.008	OOM	0.192±0.014	0.794±0.005	0.890±0.003	0.445±0.005
FTTransformer	0.335±0.010	0.161±0.022	0.140±0.002	0.277±0.004	0.335±0.003	0.445±0.003	0.361±0.018	0.345±0.005	OOM	0.106±0.012	0.826±0.005	0.896±0.007	0.461±0.003
TabNet	0.279±0.003	0.224±0.016	0.141±0.010	0.275±0.002	0.348±0.003	0.451±0.007	0.355±0.030	0.332±0.004	0.992±0.182	0.015±0.002	0.805±0.014	0.885±0.013	0.544±0.011
TabTransformer	0.624±0.003	0.229±0.003	0.369±0.005	0.340±0.004	0.388±0.002	0.539±0.003	0.619±0.005	0.351±0.001	0.893±0.005	0.431±0.001	0.819±0.002	0.886±0.005	0.545±0.004

We see that some recent deep tabular models were able to achieve competitive model performance to strong GBDTs (despite being 5--100 times slower to train). Making deep tabular models even more performant with less compute is a fruitful direction of future research.

Installation

PyTorch Frame is available for Python 3.8 to Python 3.11.

pip install pytorch_frame

See the installation guide for other options.