mirror of https://github.com/explosion/spaCy.git
704 lines
49 KiB
Markdown
704 lines
49 KiB
Markdown
---
|
||
title: Model Architectures
|
||
teaser: Pre-defined model architectures included with the core library
|
||
source: spacy/ml/models
|
||
menu:
|
||
- ['Tok2Vec', 'tok2vec-arch']
|
||
- ['Transformers', 'transformers']
|
||
- ['Parser & NER', 'parser']
|
||
- ['Tagging', 'tagger']
|
||
- ['Text Classification', 'textcat']
|
||
- ['Entity Linking', 'entitylinker']
|
||
---
|
||
|
||
A **model architecture** is a function that wires up a
|
||
[`Model`](https://thinc.ai/docs/api-model) instance, which you can then use in a
|
||
pipeline component or as a layer of a larger network. This page documents
|
||
spaCy's built-in architectures that are used for different NLP tasks. All
|
||
trainable [built-in components](/api#architecture-pipeline) expect a `model`
|
||
argument defined in the config and document their the default architecture.
|
||
Custom architectures can be registered using the
|
||
[`@spacy.registry.architectures`](/api/top-level#regsitry) decorator and used as
|
||
part of the [training config](/usage/training#custom-functions). Also see the
|
||
usage documentation on
|
||
[layers and model architectures](/usage/layers-architectures).
|
||
|
||
## Tok2Vec architectures {#tok2vec-arch source="spacy/ml/models/tok2vec.py"}
|
||
|
||
### spacy.HashEmbedCNN.v1 {#HashEmbedCNN}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.HashEmbedCNN.v1"
|
||
> pretrained_vectors = null
|
||
> width = 96
|
||
> depth = 4
|
||
> embed_size = 2000
|
||
> window_size = 1
|
||
> maxout_pieces = 3
|
||
> subword_features = true
|
||
> ```
|
||
|
||
Build spaCy's "standard" embedding layer, which uses hash embedding with subword
|
||
features and a CNN with layer-normalized maxout.
|
||
|
||
| Name | Description |
|
||
| -------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `width` | The width of the input and output. These are required to be the same, so that residual connections can be used. Recommended values are `96`, `128` or `300`. ~~int~~ |
|
||
| `depth` | The number of convolutional layers to use. Recommended values are between `2` and `8`. ~~int~~ |
|
||
| `embed_size` | The number of rows in the hash embedding tables. This can be surprisingly small, due to the use of the hash embeddings. Recommended values are between `2000` and `10000`. ~~int~~ |
|
||
| `window_size` | The number of tokens on either side to concatenate during the convolutions. The receptive field of the CNN will be `depth * (window_size * 2 + 1)`, so a 4-layer network with a window size of `2` will be sensitive to 17 words at a time. Recommended value is `1`. ~~int~~ |
|
||
| `maxout_pieces` | The number of pieces to use in the maxout non-linearity. If `1`, the [`Mish`](https://thinc.ai/docs/api-layers#mish) non-linearity is used instead. Recommended values are `1`-`3`. ~~int~~ |
|
||
| `subword_features` | Whether to also embed subword features, specifically the prefix, suffix and word shape. This is recommended for alphabetic languages like English, but not if single-character tokens are used for a language such as Chinese. ~~bool~~ |
|
||
| `pretrained_vectors` | Whether to also use static vectors. ~~bool~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
### spacy.Tok2Vec.v1 {#Tok2Vec}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.Tok2Vec.v1"
|
||
>
|
||
> [model.embed]
|
||
> @architectures = "spacy.CharacterEmbed.v1"
|
||
> # ...
|
||
>
|
||
> [model.encode]
|
||
> @architectures = "spacy.MaxoutWindowEncoder.v1"
|
||
> # ...
|
||
> ```
|
||
|
||
Construct a tok2vec model out of embedding and encoding subnetworks. See the
|
||
["Embed, Encode, Attend, Predict"](https://explosion.ai/blog/deep-learning-formula-nlp)
|
||
blog post for background.
|
||
|
||
| Name | Description |
|
||
| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `embed` | Embed tokens into context-independent word vector representations. For example, [CharacterEmbed](/api/architectures#CharacterEmbed) or [MultiHashEmbed](/api/architectures#MultiHashEmbed). ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
| `encode` | Encode context into the embeddings, using an architecture such as a CNN, BiLSTM or transformer. For example, [MaxoutWindowEncoder](/api/architectures#MaxoutWindowEncoder). ~~Model[List[Floats2d], List[Floats2d]]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
### spacy.Tok2VecListener.v1 {#Tok2VecListener}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [components.tok2vec]
|
||
> factory = "tok2vec"
|
||
>
|
||
> [components.tok2vec.model]
|
||
> @architectures = "spacy.HashEmbedCNN.v1"
|
||
> width = 342
|
||
>
|
||
> [components.tagger]
|
||
> factory = "tagger"
|
||
>
|
||
> [components.tagger.model]
|
||
> @architectures = "spacy.Tagger.v1"
|
||
>
|
||
> [components.tagger.model.tok2vec]
|
||
> @architectures = "spacy.Tok2VecListener.v1"
|
||
> width = ${components.tok2vec.model.width}
|
||
> ```
|
||
|
||
A listener is used as a sublayer within a component such as a
|
||
[`DependencyParser`](/api/dependencyparser),
|
||
[`EntityRecognizer`](/api/entityrecognizer)or
|
||
[`TextCategorizer`](/api/textcategorizer). Usually you'll have multiple
|
||
listeners connecting to a single upstream [`Tok2Vec`](/api/tok2vec) component
|
||
that's earlier in the pipeline. The listener layers act as **proxies**, passing
|
||
the predictions from the `Tok2Vec` component into downstream components, and
|
||
communicating gradients back upstream.
|
||
|
||
Instead of defining its own `Tok2Vec` instance, a model architecture like
|
||
[Tagger](/api/architectures#tagger) can define a listener as its `tok2vec`
|
||
argument that connects to the shared `tok2vec` component in the pipeline.
|
||
|
||
| Name | Description |
|
||
| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||
| `width` | The width of the vectors produced by the "upstream" [`Tok2Vec`](/api/tok2vec) component. ~~int~~ |
|
||
| `upstream` | A string to identify the "upstream" `Tok2Vec` component to communicate with. By default, the upstream name is the wildcard string `"*"`, but you could also specify the name of the `Tok2Vec` component. You'll almost never have multiple upstream `Tok2Vec` components, so the wildcard string will almost always be fine. ~~str~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
### spacy.MultiHashEmbed.v1 {#MultiHashEmbed}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.MultiHashEmbed.v1"
|
||
> width = 64
|
||
> rows = 2000
|
||
> also_embed_subwords = false
|
||
> also_use_static_vectors = false
|
||
> ```
|
||
|
||
Construct an embedding layer that separately embeds a number of lexical
|
||
attributes using hash embedding, concatenates the results, and passes it through
|
||
a feed-forward subnetwork to build a mixed representations. The features used
|
||
are the `NORM`, `PREFIX`, `SUFFIX` and `SHAPE`, which can have varying
|
||
definitions depending on the `Vocab` of the `Doc` object passed in. Vectors from
|
||
pretrained static vectors can also be incorporated into the concatenated
|
||
representation.
|
||
|
||
| Name | Description |
|
||
| ------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `width` | The output width. Also used as the width of the embedding tables. Recommended values are between `64` and `300`. ~~int~~ |
|
||
| `rows` | The number of rows for the embedding tables. Can be low, due to the hashing trick. Embeddings for prefix, suffix and word shape use half as many rows. Recommended values are between `2000` and `10000`. ~~int~~ |
|
||
| `also_embed_subwords` | Whether to use the `PREFIX`, `SUFFIX` and `SHAPE` features in the embeddings. If not using these, you may need more rows in your hash embeddings, as there will be increased chance of collisions. ~~bool~~ |
|
||
| `also_use_static_vectors` | Whether to also use static word vectors. Requires a vectors table to be loaded in the [Doc](/api/doc) objects' vocab. ~~bool~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
### spacy.CharacterEmbed.v1 {#CharacterEmbed}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.CharacterEmbed.v1"
|
||
> width = 128
|
||
> rows = 7000
|
||
> nM = 64
|
||
> nC = 8
|
||
> ```
|
||
|
||
Construct an embedded representations based on character embeddings, using a
|
||
feed-forward network. A fixed number of UTF-8 byte characters are used for each
|
||
word, taken from the beginning and end of the word equally. Padding is used in
|
||
the center for words that are too short.
|
||
|
||
For instance, let's say `nC=4`, and the word is "jumping". The characters used
|
||
will be `"jung"` (two from the start, two from the end). If we had `nC=8`, the
|
||
characters would be `"jumpping"`: 4 from the start, 4 from the end. This ensures
|
||
that the final character is always in the last position, instead of being in an
|
||
arbitrary position depending on the word length.
|
||
|
||
The characters are embedded in a embedding table with 256 rows, and the vectors
|
||
concatenated. A hash-embedded vector of the `NORM` of the word is also
|
||
concatenated on, and the result is then passed through a feed-forward network to
|
||
construct a single vector to represent the information.
|
||
|
||
| Name | Description |
|
||
| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `width` | The width of the output vector and the `NORM` hash embedding. ~~int~~ |
|
||
| `rows` | The number of rows in the `NORM` hash embedding table. ~~int~~ |
|
||
| `nM` | The dimensionality of the character embeddings. Recommended values are between `16` and `64`. ~~int~~ |
|
||
| `nC` | The number of UTF-8 bytes to embed per word. Recommended values are between `3` and `8`, although it may depend on the length of words in the language. ~~int~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
### spacy.MaxoutWindowEncoder.v1 {#MaxoutWindowEncoder}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.MaxoutWindowEncoder.v1"
|
||
> width = 128
|
||
> window_size = 1
|
||
> maxout_pieces = 3
|
||
> depth = 4
|
||
> ```
|
||
|
||
Encode context using convolutions with maxout activation, layer normalization
|
||
and residual connections.
|
||
|
||
| Name | Description |
|
||
| --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `width` | The input and output width. These are required to be the same, to allow residual connections. This value will be determined by the width of the inputs. Recommended values are between `64` and `300`. ~~int~~ |
|
||
| `window_size` | The number of words to concatenate around each token to construct the convolution. Recommended value is `1`. ~~int~~ |
|
||
| `maxout_pieces` | The number of maxout pieces to use. Recommended values are `2` or `3`. ~~int~~ |
|
||
| `depth` | The number of convolutional layers. Recommended value is `4`. ~~int~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Floats2d], List[Floats2d]]~~ |
|
||
|
||
### spacy.MishWindowEncoder.v1 {#MishWindowEncoder}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.MishWindowEncoder.v1"
|
||
> width = 64
|
||
> window_size = 1
|
||
> depth = 4
|
||
> ```
|
||
|
||
Encode context using convolutions with
|
||
[`Mish`](https://thinc.ai/docs/api-layers#mish) activation, layer normalization
|
||
and residual connections.
|
||
|
||
| Name | Description |
|
||
| ------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `width` | The input and output width. These are required to be the same, to allow residual connections. This value will be determined by the width of the inputs. Recommended values are between `64` and `300`. ~~int~~ |
|
||
| `window_size` | The number of words to concatenate around each token to construct the convolution. Recommended value is `1`. ~~int~~ |
|
||
| `depth` | The number of convolutional layers. Recommended value is `4`. ~~int~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Floats2d], List[Floats2d]]~~ |
|
||
|
||
### spacy.TorchBiLSTMEncoder.v1 {#TorchBiLSTMEncoder}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.TorchBiLSTMEncoder.v1"
|
||
> width = 64
|
||
> window_size = 1
|
||
> depth = 4
|
||
> ```
|
||
|
||
Encode context using bidirectional LSTM layers. Requires
|
||
[PyTorch](https://pytorch.org).
|
||
|
||
| Name | Description |
|
||
| ------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `width` | The input and output width. These are required to be the same, to allow residual connections. This value will be determined by the width of the inputs. Recommended values are between `64` and `300`. ~~int~~ |
|
||
| `window_size` | The number of words to concatenate around each token to construct the convolution. Recommended value is `1`. ~~int~~ |
|
||
| `depth` | The number of convolutional layers. Recommended value is `4`. ~~int~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Floats2d], List[Floats2d]]~~ |
|
||
|
||
### spacy.StaticVectors.v1 {#StaticVectors}
|
||
|
||
> #### Example config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.StaticVectors.v1"
|
||
> nO = null
|
||
> nM = null
|
||
> dropout = 0.2
|
||
> key_attr = "ORTH"
|
||
>
|
||
> [model.init_W]
|
||
> @initializers = "glorot_uniform_init.v1"
|
||
> ```
|
||
|
||
Embed [`Doc`](/api/doc) objects with their vocab's vectors table, applying a
|
||
learned linear projection to control the dimensionality. See the documentation
|
||
on [static vectors](/usage/embeddings-transformers#static-vectors) for details.
|
||
|
||
| Name | Description |
|
||
| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `nO` | The output width of the layer, after the linear projection. ~~Optional[int]~~ |
|
||
| `nM` | The width of the static vectors. ~~Optional[int]~~ |
|
||
| `dropout` | Optional dropout rate. If set, it's applied per dimension over the whole batch. Defaults to `None`. ~~Optional[float]~~ |
|
||
| `init_W` | The [initialization function](https://thinc.ai/docs/api-initializers). Defaults to [`glorot_uniform_init`](https://thinc.ai/docs/api-initializers#glorot_uniform_init). ~~Callable[[Ops, Tuple[int, ...]]], FloatsXd]~~ |
|
||
| `key_attr` | Defaults to `"ORTH"`. ~~str~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], Ragged]~~ |
|
||
|
||
## Transformer architectures {#transformers source="github.com/explosion/spacy-transformers/blob/master/spacy_transformers/architectures.py"}
|
||
|
||
The following architectures are provided by the package
|
||
[`spacy-transformers`](https://github.com/explosion/spacy-transformers). See the
|
||
[usage documentation](/usage/embeddings-transformers#transformers) for how to
|
||
integrate the architectures into your training config.
|
||
|
||
<Infobox variant="warning">
|
||
|
||
Note that in order to use these architectures in your config, you need to
|
||
install the
|
||
[`spacy-transformers`](https://github.com/explosion/spacy-transformers). See the
|
||
[installation docs](/usage/embeddings-transformers#transformers-installation)
|
||
for details and system requirements.
|
||
|
||
</Infobox>
|
||
|
||
### spacy-transformers.TransformerModel.v1 {#TransformerModel}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy-transformers.TransformerModel.v1"
|
||
> name = "roberta-base"
|
||
> tokenizer_config = {"use_fast": true}
|
||
>
|
||
> [model.get_spans]
|
||
> @span_getters = "strided_spans.v1"
|
||
> window = 128
|
||
> stride = 96
|
||
> ```
|
||
|
||
Load and wrap a transformer model from the
|
||
[HuggingFace `transformers`](https://huggingface.co/transformers) library. You
|
||
can use any transformer that has pretrained weights and a PyTorch
|
||
implementation. The `name` variable is passed through to the underlying library,
|
||
so it can be either a string or a path. If it's a string, the pretrained weights
|
||
will be downloaded via the transformers library if they are not already
|
||
available locally.
|
||
|
||
In order to support longer documents, the
|
||
[TransformerModel](/api/architectures#TransformerModel) layer allows you to pass
|
||
in a `get_spans` function that will divide up the [`Doc`](/api/doc) objects
|
||
before passing them through the transformer. Your spans are allowed to overlap
|
||
or exclude tokens. This layer is usually used directly by the
|
||
[`Transformer`](/api/transformer) component, which allows you to share the
|
||
transformer weights across your pipeline. For a layer that's configured for use
|
||
in other components, see
|
||
[Tok2VecTransformer](/api/architectures#Tok2VecTransformer).
|
||
|
||
| Name | Description |
|
||
| ------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `name` | Any model name that can be loaded by [`transformers.AutoModel`](https://huggingface.co/transformers/model_doc/auto.html#transformers.AutoModel). ~~str~~ |
|
||
| `get_spans` | Function that takes a batch of [`Doc`](/api/doc) object and returns lists of [`Span`](/api) objects to process by the transformer. [See here](/api/transformer#span_getters) for built-in options and examples. ~~Callable[[List[Doc]], List[Span]]~~ |
|
||
| `tokenizer_config` | Tokenizer settings passed to [`transformers.AutoTokenizer`](https://huggingface.co/transformers/model_doc/auto.html#transformers.AutoTokenizer). ~~Dict[str, Any]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], FullTransformerBatch]~~ |
|
||
|
||
### spacy-transformers.TransformerListener.v1 {#TransformerListener}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy-transformers.TransformerListener.v1"
|
||
> grad_factor = 1.0
|
||
>
|
||
> [model.pooling]
|
||
> @layers = "reduce_mean.v1"
|
||
> ```
|
||
|
||
Create a `TransformerListener` layer, which will connect to a
|
||
[`Transformer`](/api/transformer) component earlier in the pipeline. The layer
|
||
takes a list of [`Doc`](/api/doc) objects as input, and produces a list of
|
||
2-dimensional arrays as output, with each array having one row per token. Most
|
||
spaCy models expect a sublayer with this signature, making it easy to connect
|
||
them to a transformer model via this sublayer. Transformer models usually
|
||
operate over wordpieces, which usually don't align one-to-one against spaCy
|
||
tokens. The layer therefore requires a reduction operation in order to calculate
|
||
a single token vector given zero or more wordpiece vectors.
|
||
|
||
| Name | Description |
|
||
| ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `pooling` | A reduction layer used to calculate the token vectors based on zero or more wordpiece vectors. If in doubt, mean pooling (see [`reduce_mean`](https://thinc.ai/docs/api-layers#reduce_mean)) is usually a good choice. ~~Model[Ragged, Floats2d]~~ |
|
||
| `grad_factor` | Reweight gradients from the component before passing them upstream. You can set this to `0` to "freeze" the transformer weights with respect to the component, or use it to make some components more significant than others. Leaving it at `1.0` is usually fine. ~~float~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
### spacy-transformers.Tok2VecTransformer.v1 {#Tok2VecTransformer}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.Tok2VecTransformer.v1"
|
||
> name = "albert-base-v2"
|
||
> tokenizer_config = {"use_fast": false}
|
||
> grad_factor = 1.0
|
||
> ```
|
||
|
||
Use a transformer as a [`Tok2Vec`](/api/tok2vec) layer directly. This does
|
||
**not** allow multiple components to share the transformer weights, and does
|
||
**not** allow the transformer to set annotations into the [`Doc`](/api/doc)
|
||
object, but it's a **simpler solution** if you only need the transformer within
|
||
one component.
|
||
|
||
| Name | Description |
|
||
| ------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `get_spans` | Function that takes a batch of [`Doc`](/api/doc) object and returns lists of [`Span`](/api) objects to process by the transformer. [See here](/api/transformer#span_getters) for built-in options and examples. ~~Callable[[List[Doc]], List[Span]]~~ |
|
||
| `tokenizer_config` | Tokenizer settings passed to [`transformers.AutoTokenizer`](https://huggingface.co/transformers/model_doc/auto.html#transformers.AutoTokenizer). ~~Dict[str, Any]~~ |
|
||
| `pooling` | A reduction layer used to calculate the token vectors based on zero or more wordpiece vectors. If in doubt, mean pooling (see [`reduce_mean`](https://thinc.ai/docs/api-layers#reduce_mean)) is usually a good choice. ~~Model[Ragged, Floats2d]~~ |
|
||
| `grad_factor` | Reweight gradients from the component before passing them upstream. You can set this to `0` to "freeze" the transformer weights with respect to the component, or use it to make some components more significant than others. Leaving it at `1.0` is usually fine. ~~float~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
## Parser & NER architectures {#parser}
|
||
|
||
### spacy.TransitionBasedParser.v1 {#TransitionBasedParser source="spacy/ml/models/parser.py"}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.TransitionBasedParser.v1"
|
||
> nr_feature_tokens = 6
|
||
> hidden_width = 64
|
||
> maxout_pieces = 2
|
||
>
|
||
> [model.tok2vec]
|
||
> @architectures = "spacy.HashEmbedCNN.v1"
|
||
> pretrained_vectors = null
|
||
> width = 96
|
||
> depth = 4
|
||
> embed_size = 2000
|
||
> window_size = 1
|
||
> maxout_pieces = 3
|
||
> subword_features = true
|
||
> ```
|
||
|
||
Build a transition-based parser model. Can apply to NER or dependency parsing.
|
||
Transition-based parsing is an approach to structured prediction where the task
|
||
of predicting the structure is mapped to a series of state transitions. You
|
||
might find [this tutorial](https://explosion.ai/blog/parsing-english-in-python)
|
||
helpful for background information. The neural network state prediction model
|
||
consists of either two or three subnetworks:
|
||
|
||
- **tok2vec**: Map each token into a vector representations. This subnetwork is
|
||
run once for each batch.
|
||
- **lower**: Construct a feature-specific vector for each `(token, feature)`
|
||
pair. This is also run once for each batch. Constructing the state
|
||
representation is then simply a matter of summing the component features and
|
||
applying the non-linearity.
|
||
- **upper** (optional): A feed-forward network that predicts scores from the
|
||
state representation. If not present, the output from the lower model is used
|
||
as action scores directly.
|
||
|
||
| Name | Description |
|
||
| ------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `tok2vec` | Subnetwork to map tokens into vector representations. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
| `nr_feature_tokens` | The number of tokens in the context to use to construct the state vector. Valid choices are `1`, `2`, `3`, `6`, `8` and `13`. The `2`, `8` and `13` feature sets are designed for the parser, while the `3` and `6` feature sets are designed for the entity recognizer. The recommended feature sets are `3` for NER, and `8` for the dependency parser. ~~int~~ |
|
||
| `hidden_width` | The width of the hidden layer. ~~int~~ |
|
||
| `maxout_pieces` | How many pieces to use in the state prediction layer. Recommended values are `1`, `2` or `3`. If `1`, the maxout non-linearity is replaced with a [`Relu`](https://thinc.ai/docs/api-layers#relu) non-linearity if `use_upper` is `True`, and no non-linearity if `False`. ~~int~~ |
|
||
| `use_upper` | Whether to use an additional hidden layer after the state vector in order to predict the action scores. It is recommended to set this to `False` for large pretrained models such as transformers, and `True` for smaller networks. The upper layer is computed on CPU, which becomes a bottleneck on larger GPU-based models, where it's also less necessary. ~~bool~~ |
|
||
| `nO` | The number of actions the model will predict between. Usually inferred from data at the beginning of training, or loaded from disk. ~~int~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Docs], List[List[Floats2d]]]~~ |
|
||
|
||
### spacy.BILUOTagger.v1 {#BILUOTagger source="spacy/ml/models/simple_ner.py"}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.BILUOTagger.v1 "
|
||
>
|
||
> [model.tok2vec]
|
||
> @architectures = "spacy.HashEmbedCNN.v1"
|
||
> # etc.
|
||
> ```
|
||
|
||
Construct a simple NER tagger that predicts
|
||
[BILUO](/usage/linguistic-features#accessing-ner) tag scores for each token and
|
||
uses greedy decoding with transition-constraints to return a valid BILUO tag
|
||
sequence. A BILUO tag sequence encodes a sequence of non-overlapping labelled
|
||
spans into tags assigned to each token. The first token of a span is given the
|
||
tag `B-LABEL`, the last token of the span is given the tag `L-LABEL`, and tokens
|
||
within the span are given the tag `U-LABEL`. Single-token spans are given the
|
||
tag `U-LABEL`. All other tokens are assigned the tag `O`. The BILUO tag scheme
|
||
generally results in better linear separation between classes, especially for
|
||
non-CRF models, because there are more distinct classes for the different
|
||
situations ([Ratinov et al., 2009](https://www.aclweb.org/anthology/W09-1119/)).
|
||
|
||
| Name | Description |
|
||
| ----------- | ------------------------------------------------------------------------------------------ |
|
||
| `tok2vec` | Subnetwork to map tokens into vector representations. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
### spacy.IOBTagger.v1 {#IOBTagger source="spacy/ml/models/simple_ner.py"}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.IOBTagger.v1 "
|
||
>
|
||
> [model.tok2vec]
|
||
> @architectures = "spacy.HashEmbedCNN.v1"
|
||
> # etc.
|
||
> ```
|
||
|
||
Construct a simple NER tagger, that predicts
|
||
[IOB](/usage/linguistic-features#accessing-ner) tag scores for each token and
|
||
uses greedy decoding with transition-constraints to return a valid IOB tag
|
||
sequence. An IOB tag sequence encodes a sequence of non-overlapping labeled
|
||
spans into tags assigned to each token. The first token of a span is given the
|
||
tag B-LABEL, and subsequent tokens are given the tag I-LABEL. All other tokens
|
||
are assigned the tag O.
|
||
|
||
| Name | Description |
|
||
| ----------- | ------------------------------------------------------------------------------------------ |
|
||
| `tok2vec` | Subnetwork to map tokens into vector representations. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
## Tagging architectures {#tagger source="spacy/ml/models/tagger.py"}
|
||
|
||
### spacy.Tagger.v1 {#Tagger}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.Tagger.v1"
|
||
> nO = null
|
||
>
|
||
> [model.tok2vec]
|
||
> # ...
|
||
> ```
|
||
|
||
Build a tagger model, using a provided token-to-vector component. The tagger
|
||
model simply adds a linear layer with softmax activation to predict scores given
|
||
the token vectors.
|
||
|
||
| Name | Description |
|
||
| ----------- | ------------------------------------------------------------------------------------------ |
|
||
| `tok2vec` | Subnetwork to map tokens into vector representations. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
| `nO` | The number of tags to output. Inferred from the data if `None`. ~~Optional[int]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], List[Floats2d]]~~ |
|
||
|
||
## Text classification architectures {#textcat source="spacy/ml/models/textcat.py"}
|
||
|
||
A text classification architecture needs to take a [`Doc`](/api/doc) as input,
|
||
and produce a score for each potential label class. Textcat challenges can be
|
||
binary (e.g. sentiment analysis) or involve multiple possible labels.
|
||
Multi-label challenges can either have mutually exclusive labels (each example
|
||
has exactly one label), or multiple labels may be applicable at the same time.
|
||
|
||
As the properties of text classification problems can vary widely, we provide
|
||
several different built-in architectures. It is recommended to experiment with
|
||
different architectures and settings to determine what works best on your
|
||
specific data and challenge.
|
||
|
||
### spacy.TextCatEnsemble.v1 {#TextCatEnsemble}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.TextCatEnsemble.v1"
|
||
> exclusive_classes = false
|
||
> pretrained_vectors = null
|
||
> width = 64
|
||
> embed_size = 2000
|
||
> conv_depth = 2
|
||
> window_size = 1
|
||
> ngram_size = 1
|
||
> dropout = null
|
||
> nO = null
|
||
> ```
|
||
|
||
Stacked ensemble of a bag-of-words model and a neural network model. The neural
|
||
network has an internal CNN Tok2Vec layer and uses attention.
|
||
|
||
| Name | Description |
|
||
| -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `exclusive_classes` | Whether or not categories are mutually exclusive. ~~bool~~ |
|
||
| `pretrained_vectors` | Whether or not pretrained vectors will be used in addition to the feature vectors. ~~bool~~ |
|
||
| `width` | Output dimension of the feature encoding step. ~~int~~ |
|
||
| `embed_size` | Input dimension of the feature encoding step. ~~int~~ |
|
||
| `conv_depth` | Depth of the tok2vec layer. ~~int~~ |
|
||
| `window_size` | The number of contextual vectors to [concatenate](https://thinc.ai/docs/api-layers#expand_window) from the left and from the right. ~~int~~ |
|
||
| `ngram_size` | Determines the maximum length of the n-grams in the BOW model. For instance, `ngram_size=3`would give unigram, trigram and bigram features. ~~int~~ |
|
||
| `dropout` | The dropout rate. ~~float~~ |
|
||
| `nO` | Output dimension, determined by the number of different labels. If not set, the [`TextCategorizer`](/api/textcategorizer) component will set it when `begin_training` is called. ~~Optional[int]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], Floats2d]~~ |
|
||
|
||
### spacy.TextCatCNN.v1 {#TextCatCNN}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.TextCatCNN.v1"
|
||
> exclusive_classes = false
|
||
> nO = null
|
||
>
|
||
> [model.tok2vec]
|
||
> @architectures = "spacy.HashEmbedCNN.v1"
|
||
> pretrained_vectors = null
|
||
> width = 96
|
||
> depth = 4
|
||
> embed_size = 2000
|
||
> window_size = 1
|
||
> maxout_pieces = 3
|
||
> subword_features = true
|
||
> ```
|
||
|
||
A neural network model where token vectors are calculated using a CNN. The
|
||
vectors are mean pooled and used as features in a feed-forward network. This
|
||
architecture is usually less accurate than the ensemble, but runs faster.
|
||
|
||
| Name | Description |
|
||
| ------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `exclusive_classes` | Whether or not categories are mutually exclusive. ~~bool~~ |
|
||
| `tok2vec` | The [`tok2vec`](#tok2vec) layer of the model. ~~Model~~ |
|
||
| `nO` | Output dimension, determined by the number of different labels. If not set, the [`TextCategorizer`](/api/textcategorizer) component will set it when `begin_training` is called. ~~Optional[int]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], Floats2d]~~ |
|
||
|
||
### spacy.TextCatBOW.v1 {#TextCatBOW}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.TextCatBOW.v1"
|
||
> exclusive_classes = false
|
||
> ngram_size = 1
|
||
> no_output_layer = false
|
||
> nO = null
|
||
> ```
|
||
|
||
An ngram "bag-of-words" model. This architecture should run much faster than the
|
||
others, but may not be as accurate, especially if texts are short.
|
||
|
||
| Name | Description |
|
||
| ------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `exclusive_classes` | Whether or not categories are mutually exclusive. ~~bool~~ |
|
||
| `ngram_size` | Determines the maximum length of the n-grams in the BOW model. For instance, `ngram_size=3`would give unigram, trigram and bigram features. ~~int~~ |
|
||
| `no_output_layer` | Whether or not to add an output layer to the model (`Softmax` activation if `exclusive_classes` is `True`, else `Logistic`. ~~bool~~ |
|
||
| `nO` | Output dimension, determined by the number of different labels. If not set, the [`TextCategorizer`](/api/textcategorizer) component will set it when `begin_training` is called. ~~Optional[int]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], Floats2d]~~ |
|
||
|
||
## Entity linking architectures {#entitylinker source="spacy/ml/models/entity_linker.py"}
|
||
|
||
An [`EntityLinker`](/api/entitylinker) component disambiguates textual mentions
|
||
(tagged as named entities) to unique identifiers, grounding the named entities
|
||
into the "real world". This requires 3 main components:
|
||
|
||
- A [`KnowledgeBase`](/api/kb) (KB) holding the unique identifiers, potential
|
||
synonyms and prior probabilities.
|
||
- A candidate generation step to produce a set of likely identifiers, given a
|
||
certain textual mention.
|
||
- A Machine learning [`Model`](https://thinc.ai/docs/api-model) that picks the
|
||
most plausible ID from the set of candidates.
|
||
|
||
### spacy.EntityLinker.v1 {#EntityLinker}
|
||
|
||
> #### Example Config
|
||
>
|
||
> ```ini
|
||
> [model]
|
||
> @architectures = "spacy.EntityLinker.v1"
|
||
> nO = null
|
||
>
|
||
> [model.tok2vec]
|
||
> @architectures = "spacy.HashEmbedCNN.v1"
|
||
> pretrained_vectors = null
|
||
> width = 96
|
||
> depth = 2
|
||
> embed_size = 300
|
||
> window_size = 1
|
||
> maxout_pieces = 3
|
||
> subword_features = true
|
||
>
|
||
> [kb_loader]
|
||
> @assets = "spacy.EmptyKB.v1"
|
||
> entity_vector_length = 64
|
||
>
|
||
> [get_candidates]
|
||
> @assets = "spacy.CandidateGenerator.v1"
|
||
> ```
|
||
|
||
The `EntityLinker` model architecture is a Thinc `Model` with a
|
||
[`Linear`](https://thinc.ai/api-layers#linear) output layer.
|
||
|
||
| Name | Description |
|
||
| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `tok2vec` | The [`tok2vec`](#tok2vec) layer of the model. ~~Model~~ |
|
||
| `nO` | Output dimension, determined by the length of the vectors encoding each entity in the KB. If the `nO` dimension is not set, the entity linking component will set it when `begin_training` is called. ~~Optional[int]~~ |
|
||
| **CREATES** | The model using the architecture. ~~Model[List[Doc], Floats2d]~~ |
|
||
|
||
### spacy.EmptyKB.v1 {#EmptyKB}
|
||
|
||
A function that creates a default, empty `KnowledgeBase` from a
|
||
[`Vocab`](/api/vocab) instance.
|
||
|
||
| Name | Description |
|
||
| ---------------------- | ----------------------------------------------------------------------------------- |
|
||
| `entity_vector_length` | The length of the vectors encoding each entity in the KB. Defaults to `64`. ~~int~~ |
|
||
|
||
### spacy.CandidateGenerator.v1 {#CandidateGenerator}
|
||
|
||
A function that takes as input a [`KnowledgeBase`](/api/kb) and a
|
||
[`Span`](/api/span) object denoting a named entity, and returns a list of
|
||
plausible [`Candidate`](/api/kb/#candidate) objects. The default
|
||
`CandidateGenerator` simply uses the text of a mention to find its potential
|
||
aliases in the `KnowledgeBase`. Note that this function is case-dependent.
|