Introduction

Fork of Shawn Ng's CNNs for Sentence Classification in PyTorch, refactored as a scikit-learn classifier.

Requirements

• python 3
• pytorch > 0.1
• torchtext > 0.1
• numpy
• scikit-learn

Known Issues

• The predict and predict_proba methods are probably not as efficient as they could be.
• The class probabilities returned by the predict_proba method are probably questionable.
• Doesn't play well with GridSearchCV if num_jobs isn't 1 (unless not using CUDA).
• Only supports pre-trained word vectors from TorchText (or no pre-trained vectors).
• The random_state parameter probably only works with integers or None.
• Features my idiosyncratic coding style.

To Do

• Add support for cross-validation during training.
• Implement sample weights in eval scoring?

Parameters

lr : float, optional (default=0.01) Initial learning rate.

epochs : integer, optional (default=256) Number of training epochs.

batch_size : integer, optional (default=64) Training batch size.

test_interval : integer, optional (default=100) The number of epochs to wait before testing.

early_stop : integer, optional (default=1000) The number of iterations without increased performance to reach before stopping.

save_best : boolean, optional (default=True) Keep the model with the best performance found during training.

dropout : float, optional (default=0.5) Dropout probability.

max_norm : float, optional (default=0.0) L2 constraint.

embed_dim : integer, optional (default=128) The number of embedding dimensions. Ignored if vectors is not None.

kernel_num : integer, optional (default=100) The number of each size of kernel.

kernel_sizes : iterable of integers, optional (default=(3, 4, 5)) Kernel sizes to use for convolution.

static : boolean, optional (default=False) If true, fix the embedding.

device : int, optional (default=-1) Device to use for iterating data; -1 for CPU (see torch.cuda.set_device()).

cuda : boolean, optional (default=True) If true, use the GPU if available.

** activation_func : string, optional (default='relu')** Activation function. If 'relu' or 'tanh', uses rectified linear unit or hyperbolic tangent, respectively. Otherwise, uses no activation function (f(x) = x).

scoring : callable or None, optional (default=sklearn.metrics.accuracy_score) Scoring method for testing model performance during fitting.

vectors : string, optional (default=None) Which pretrained TorchText vectors to use (see torchtext.vocab.pretrained_aliases for options).

split_ratio : float, optional (default=0.9) Ratio of training data used for training. The remainder will be used for validation.

preprocessor : callable or None, optional (default=None) Override default string preprocessing.

class_weight : dict, "balanced" or None, optional (default=None) Weights associated with each class (see class_weight parameter in existing scikit-learn classifiers).

random_state : integer, optional (default=None) Seed for the random number generator.

verbose : integer, optional (default=0) Controls the verbosity when fitting.

Methods

fit(X, y, sample_weight=None) Train the CNN classifier from the training set (X, y).

Parameters: X: list of strings
               The training input samples.

            y: list of strings
               The class labels.

            sample_weight: list of integers or floats, or None
               Sample weights. If None, samples are equally weighted.

Returns:    self : object

predict(X) Predict class for X.

Parameters: X: list of strings
               The input samples.

Returns:    y: list of strings
               The predicted classes.

predict_proba(X) Predict class probabilities for X.

Parameters: X: list of strings
               The input samples.

Returns:    y: list of lists for floats
               The predicted class probabilities.