Snips NLU Metrics

This tools is a python library for computing cross-validation and train/test metrics on an NLU parsing pipeline such as the Snips NLU one.

Its purpose is to help evaluating and iterating on the tested intent parsing pipeline.

Install

$ pip install snips_nlu_metrics

NLU Metrics API

Snips NLU metrics API consists in the following functions:

• compute_train_test_metrics to compute train/test metrics
• compute_cross_val_metrics to compute cross-validation metrics

The metrics output (json) provides detailed information about:

• confusion matrix
• precision, recall and f1 scores of intent classification
• precision, recall and f1 scores of entity extraction
• parsing errors

Data

Some sample datasets, that can be used to compute metrics, are available here. Alternatively, you can create your own dataset either by using snips-nlu's dataset generation tool or by going on the Snips console.

Examples

The Snips NLU metrics library can be used with any NLU pipeline which satisfies the Engine API:

from builtins import object

class Engine(object):
    def fit(self, dataset):
        # Perform training ...
        return self

    def parse(self, text):
        # extract intent and slots ...
        return {
            "input": text,
            "intent": {
                "intentName": intent_name,
                "probability": probability
            },
            "slots": slots
        }

Snips NLU Engine

This library can be used to benchmark NLU solutions such as Snips NLU. To install the snips-nlu python library, and fetch the language resources for english, run the following commands:

$ pip install snips-nlu
$ snips-nlu download en

Then, you can compute metrics for the snips-nlu pipeline using the metrics API as follows:

from snips_nlu import SnipsNLUEngine
from snips_nlu_metrics import compute_train_test_metrics, compute_cross_val_metrics

tt_metrics = compute_train_test_metrics(train_dataset="samples/train_dataset.json",
                                        test_dataset="samples/test_dataset.json",
                                        engine_class=SnipsNLUEngine)

cv_metrics = compute_cross_val_metrics(dataset="samples/cross_val_dataset.json",
                                       engine_class=SnipsNLUEngine,
                                       nb_folds=5)

Custom NLU Engine

You can also compute metrics on a custom NLU engine, here is a simple example:

import random

from snips_nlu_metrics import compute_train_test_metrics

class MyNLUEngine(object):
    def fit(self, dataset):
        self.intent_list = list(dataset["intents"])
        return self

    def parse(self, text):
        return {
            "input": text,
            "intent": {
                "intentName": random.choice(self.intent_list),
                "probability": 0.5
            },
            "slots": []
        }

compute_train_test_metrics(train_dataset="samples/train_dataset.json",
                           test_dataset="samples/test_dataset.json",
                           engine_class=MyNLUEngine)

Links

• Changelog
• Bug tracker
• Snips NLU
• Snips NLU Rust: Rust inference pipeline implementation and bindings (C, Swift, Kotlin, Python)
• Snips

Contributing

Please see the Contribution Guidelines.

Copyright

This library is provided by Snips as Open Source software. See LICENSE for more information.