PyTorch Tabular is a powerful library that aims to simplify and popularize the application of deep learning techniques to tabular data. Tabular deep learning has gained significant importance in the field of machine learning due to its ability to handle structured data, such as data in spreadsheets or databases. However, working with tabular data can be challenging, requiring expertise in both deep learning and data preprocessing. https://pytorch-tabular.readthedocs.io/en/latest/

Data for amex-default-prediction Collected with amex-ptls-data-preprocessing Example of dataset usage ptls-data-usage

The MELD Preprocessed Dataset is a multi-modal dataset designed for research on emotion recognition from audio, video, and textual data. The dataset builds upon the original MELD dataset and applies extensive preprocessing steps to extract features from different modalities. Each sample is saved as a .pt file containing a dictionary of preprocessed features, making it easy for developers to load and integrate into PyTorch-based workflows.

Data Sources

• Audio: Waveforms extracted from the original video files.
• Video: Video files are processed to sample frames at a target frame rate (default: 2 fps) and to detect faces using a Haar Cascade classifier.
• Text: Utterances from the dialogue, which are cleaned using custom encoding functions to fix potential byte encoding issues.
• Emotion Labels: Each sample is associated with an emotion label.

Preprocessing Pipeline

The preprocessing script performs several key steps:

1. Text Cleaning:

   • fix_encoding_with_bytes(text): Decodes text from bytes using UTF-8, Latin-1, or cp1252, ensuring correct encoding.
   • replace_double_encoding(text): Fixes issues related to double-encoded characters (e.g., replacing "Â’" with the proper apostrophe).

2. Audio Processing:

   • Extracts raw audio waveform from each sample.
   • Computes a Mel-spectrogram using torchaudio.transforms.MelSpectrogram with 64 mel bins (VGGish format).
   • Converts the spectrogram to a logarithmic scale for numerical stability.

3. Video Processing:

   • Reads video frames at a specified target FPS (default: 2 fps) using OpenCV.
   • For each video, samples frames evenly based on the original video's FPS.
   • Applies Haar Cascade face detection on the frames to extract the first detected face.
   • Resizes the detected face to 224x224 and converts it to RGB. If no face is detected, a default black image (224x224x3) is returned.

4. Saving Processed Samples:

   • Each sample is saved as a .pt file in a directory structure split by data type (train, dev, and test).
   • The filename is derived from the original video filename (e.g., dia0_utt1.mp4 becomes dia0_utt1.pt).

Data Format

Each preprocessed sample is stored in a .pt file and contains a dictionary with the following keys:

• utterance (str): The cleaned textual utterance.
• emotion (str/int): The corresponding emotion label.
• video_path (str): Original path to the video file from which the sample was extracted.
• audio (Tensor): Raw audio waveform tensor of shape [channels, time].
• audio_sample_rate (int): The sampling rate of the audio waveform.
• audio_mel (Tensor): The computed log-scaled Mel-spectrogram with shape [channels, n_mels, time].
• face (NumPy array): The extracted face image (RGB format) of shape (224, 224, 3). If no face was detected, a default black image is provided.

Directory Structure

The preprocessed files are organized into splits: preprocessed_data/ ├── train/ │ ├── dia0_utt0.pt │ ├── dia1_utt1.pt │ └── ... ├── dev/ │ ├── dia0_utt0.pt │ ├── dia1_utt1.pt │ └── ... └── test/ │ ├── dia0_utt0.pt │ ├── dia1_utt1.pt └── ...

Loading and Using the Dataset

A custom PyTorch dataset and DataLoader are provided to facilitate easy integration:

Dataset Class

from torch.utils.data import Dataset
import os
import torch

class PreprocessedMELDDataset(Dataset):
  def _init_(self, data_dir):
    """
    Args:
      data_dir (str): Directory where preprocessed .pt files are stored.
    """
    self.data_dir = data_dir
    self.files = [os.path.join(data_dir, f) for f in os.listdir(data_dir) if f.endswith('.pt')]
    
  def _len_(self):
    return len(self.files)
  
  def _getitem_(self, idx):
    sample_path = self.files[idx]
    sample = torch.load(sample_path)
    return sample

Custom Collate Function

def preprocessed_collate_fn(batch):
  """
  Collates a list of sample dictionaries into a single dictionary with keys mapping to lists.
  Modify this function to pad or stack tensor data if needed.
  """
  collated = {}
  collated['utterance'] = [sample['utterance'] for sample in batch]
  collated['emotion'] = [sample['emotion'] for sample in batch]
  collated['video_path'] = [sample['video_path'] for sample in batch]
  collated['audio'] = [sample['audio'] for sample in batch]
  collated['audio_sample_rate'] = batch[0]['audio_sample_rate']
  collated['audio_mel'] = [sample['audio_mel'] for sample in batch]
  collated['face'] = [sample['face'] for sample in batch]
  return collated

Creating DataLoaders

from torch.utils.data import DataLoader

# Define paths for each split
train_data_dir = "preprocessed_data/train"
dev_data_dir = "preproces...

Feral Cat Segmentation Dataset

Overview

This dataset provides image segmentation data for feral cats, designed for computer vision and machine learning tasks. It builds upon the original public domain dataset by Paul Cashman from Roboflow, with additional preprocessing and multiple data formats for easier consumption.

Dataset Source

• Original Author: Paul Cashman
• Original Source: Roboflow Universe
• Extended by: Lu Hou Yang
• GitHub: https://github.com/luhouyang/open_circles
• License: Public Domain

Dataset Contents

The dataset is organized into three standard splits: - Train set - Validation set - Test set

Each split contains data in multiple formats: 1. Original JPG images 2. Segmentation mask JPG images 3. Parquet files containing flattened image and mask data 4. Pickle files containing serialized image and mask data

Data Formats

1. Image Files

• Format: JPG
• Resolution: 224×224 pixels
• Directory Structure:
  • train/: Original training images
  • valid/: Original validation images
  • test/: Original test images
  • train_mask/: Corresponding segmentation masks for training
  • valid_mask/: Corresponding segmentation masks for validation
  • test_mask/: Corresponding segmentation masks for testing

2. Parquet Files

• Files: train_dataset.parquet, valid_dataset.parquet, test_dataset.parquet
• Content: Flattened image data and corresponding masks combined in a single table
• Structure: Each row contains the flattened pixel values of an image followed by the flattened pixel values of its mask
• Data Division: Image and mask data are split at index split_at = image_size[0] * image_size[1] * image_channels
  • Data before this index: image pixel values (reshaped to [-1, 224, 224, 3])
  • Data after this index: mask pixel values (reshaped to [-1, 224, 224, 1])
• Benefits: Efficient storage and faster loading compared to individual image files

3. Pickle Files

• Files: train_dataset.pkl, valid_dataset.pkl, test_dataset.pkl
• Content: Serialized Python objects containing images and their corresponding masks
• Structure: List of [image, mask] pairs, where each image and mask is serialized using Python's pickle
• Data Access: Similar to parquet files, when loaded through the provided dataset class, data is split at the same index: split_at = image_size[0] * image_size[1] * image_channels
• Benefits: Preserves original data structure and enables quick loading in Python

4. CSV Files

• Files: train_dataset.csv, valid_dataset.csv, test_dataset.csv
• Content: Same data as parquet files but in CSV format
• Structure: No headers, raw flattened pixel values
• Data Division: Same split point as parquet files

Image Preprocessing

All images were preprocessed with the following operations: - Resized to 224×224 pixels using bilinear interpolation - Segmentation masks were also resized to match the images using nearest neighbor interpolation - Original RLE (Run-Length Encoding) segmentation data converted to binary masks

Data Normalization

When used with the provided PyTorch dataset class, images are normalized with: - Mean: [0.48235, 0.45882, 0.40784] - Standard Deviation: [0.00392156862745098, 0.00392156862745098, 0.00392156862745098]

PyTorch Integration

A custom CatDataset class is included for easy integration with PyTorch:

from cat_dataset import CatDataset

# Load from parquet format
dataset = CatDataset(
  root="path/to/dataset",
  split="train", # Options: "train", "valid", "test"
  format="parquet", # Options: "parquet", "pkl"
  image_size=[224, 224],
  image_channels=3,
  mask_channels=1
)

# Use with PyTorch DataLoader
from torch.utils.data import DataLoader
dataloader = DataLoader(dataset, batch_size=32, shuffle=True)

Performance Comparison

Loading time benchmarks from the original implementation: - Parquet format: ~1.29 seconds per iteration - Pickle format: ~0.71 seconds per iteration

The pickle format provides the fastest loading times and is recommended for most use cases.

Citation

If you use this dataset in your research or projects, please cite:

@misc{feral-cat-segmentation_dataset,
 title = {feral-cat-segmentation Dataset},
 type = {Open Source Dataset},
 author = {Paul Cashman},
 howpublished = {\url{https://universe.roboflow.com/paul-cashman-mxgwb/feral-cat-segmentation}},
 url = {https://universe.roboflow.com/paul-cashman-mxgwb/feral-cat-segmentation},
 journal = {Roboflow Universe},
 publisher = {Roboflow},
 year = {2025},
 month = {mar},
 note = {visited on 2025-03-19},
}

Sample Usage Code

Basic Dataset Loading

from ca...

Star-Wars-Chatbot

Simple chatbot implementation with PyTorch. A chatbot made in Python that features various data about the Star Wars universe. This is a generic chatbot. Can be trained on pretty much any conversation as long as formatted correctly JSON file. I used it for a final project in Artificial Intelligence. To use just run the script training first, then run your chatbot. For more please have a look on GitHub

Introduction

Chatbots are extremely helpful for business organizations and also the customers. The majority of people prefer to talk directly from a chatbox instead of calling service centers. Today I am going to build an exciting project on Chatbot. I will implement a chatbot from scratch that will be able to understand what the user is talking about and give an appropriate response. Chatbots are nothing but an intelligent piece of software that can interact and communicate with people just like humans. Here in this project we created an AI Chatbot which is focused for The Star Wars Cinematic Universe and trying training it in such a way that it can answer some of the basics queries about Star Wars.

Explanation Of Chatbot

Chatbots are basically AI intelligence bots which can interact with the user or customers depends upon the usage. It is an application of Artificial Intelligence and Machine Learning¬. Now-a-days technology is increasing rapidly. In this technological world every industry is trying to automate things to provide better services. One of the great application of automation would be chatbot.

There are basically two types of Chatbots :

• Command based: Chatbots that function on predefined rules and can answer to only limited queries or questions. Users need to select an option to determine their next step.
• Intelligent/AI Chatbots: Chatbots that leverage Machine Learning and Natural Language Understanding to understand the user’s language and are intelligent enough to learn from conversations with their users. You can converse via text, speech or even interact with a chatbot using graphical interfaces.

All chatbots come under the NLP (Natural Language Processing) concepts. NLP is composed of two things: - NLU (Natural Language Understanding): The ability of machines to understand human language like English. - NLG (Natural Language Generation): The ability of a machine to generate text similar to human written sentences Imagine a user asking a question to a chatbot: “Hey, what’s on the news today?” The chatbot will break down the user sentence into two things: intent and an entity. The intent for this sentence could be get_news as it refers to an action the user wants to perform. The entity tells specific details about the intent, so "today" will be the entity. So this way, a machine learning model is used to recognize the intents and entities of the chat.

Strategy

• Import Libraries and Load the Data
• Preprocessing the Data
• Create Training and Testing Data
• Training the Model
• Graphical user interface

Import Libraries and Load the Data

I created a new python file and name it as chatbot.py and then import all the required modules. After that I loaded starwarsintents.json data file in our Python program.

import numpy as np
import nltk
from nltk.stem.porter import PorterStemmer

stemmer = PorterStemmer()
import torch
import torch.nn as nn
import random
import json
from torch.utils.data import Dataset, DataLoader
from tkinter import *

with open("starwarsintents.json", "r") as f:
  intents = json.load(f)
 ```

## Preprocessing the Data

- Creating Custom Functions:

We will create custom Functions so that it is easy for us to implement afterwards. Natural language (nltk) took kit is a really useful library that contains important classes that will be useful in any of your NLP task. To know a bit more about Natural language (nltk). Please click [here](https://machinelearningmastery.com/natural-language-processing/) for more information.

- Stemming:

If we have 3 words like “walk”, “walked”, “walking”, these might seem different words but they generally have the same meaning and also have the same base form; “walk”. So, in order for our model to understand all different form of the same words we need to train our model with that form. This is called Stemming. There are different methods that we can use for stemming. Here we will use Porter Stemmer model form our NLTK Library. For more information click [here](http://snowball.tartarus.org/algorithms/porter/stemmer.html).

- Bag of Words:

We will be splitting each word in the sentences and adding it to an array. We will be using bag of words. Which will initially be a list of zeros with the size equal to the length of the all words array.If we have a array of sentences = ["hello", "how", "are", "you"] and an array of total words = ["hi", "hel...