pombredanne / ramp

Rapid Machine Learning Prototyping in Python

Ramp - Rapid Machine Learning Prototyping

Ramp is a python library for rapid prototyping of machine learning solutions. It's a light-weight pandas-based machine learning framework pluggable with existing python machine learning and statistics tools (scikit-learn, rpy2, etc.). Ramp provides a simple, declarative syntax for exploring features, algorithms and transformations quickly and efficiently.

Documentation: http://ramp.readthedocs.org

Why Ramp?

• Clean, declarative syntax

• Complex feature transformations

  Chain and combine features:

Normalize(Log('x'))
Interactions([Log('x1'), (F('x2') + F('x3')) / 2])

Reduce feature dimension:

DimensionReduction([F('x%d'%i) for i in range(100)], decomposer=PCA(n_components=3))

Incorporate residuals or predictions to blend with other models:

Residuals(simple_model_def) + Predictions(complex_model_def)

• Data context awareness

  Any feature that uses the target ("y") variable will automatically respect the current training and test sets. Similarly, preparation data (a feature's mean and stdev, for example) is stored and tracked between data contexts.

• Composability

  All features, estimators, and their fits are composable, pluggable and storable.

• Easy extensibility

  Ramp has a simple API, allowing you to plug in estimators from scikit-learn, rpy2 and elsewhere, or easily build your own feature transformations, metrics, feature selectors, reporters, or estimators.

Quick start

Getting started with Ramp: Classifying insults

Or, the quintessential Iris example:

import pandas
from ramp import *
import urllib2
import sklearn
from sklearn import decomposition


# fetch and clean iris data from UCI
data = pandas.read_csv(urllib2.urlopen(
    "http://archive.ics.uci.edu/ml/machine-learning-databases/iris/iris.data"))
data = data.drop([149]) # bad line
columns = ['sepal_length', 'sepal_width', 'petal_length', 'petal_width', 'class']
data.columns = columns


# all features
features = [FillMissing(f, 0) for f in columns[:-1]]

# features, log transformed features, and interaction terms
expanded_features = (
    features +
    [Log(F(f) + 1) for f in features] +
    [
        F('sepal_width') ** 2,
        combo.Interactions(features),
    ]
)


# Define several models and feature sets to explore,
# run 5 fold cross-validation on each and print the results.
# We define 2 models and 4 feature sets, so this will be
# 4 * 2 = 8 models tested.
shortcuts.cv_factory(
    data=data,

    target=[AsFactor('class')],
    metrics=[
        [metrics.GeneralizedMCC()],
        ],
    # report feature importance scores from Random Forest
    reporters=[
        [reporters.RFImportance()],
        ],

    # Try out two algorithms
    model=[
        sklearn.ensemble.RandomForestClassifier(
            n_estimators=20),
        sklearn.linear_model.LogisticRegression(),
        ],

    # and 4 feature sets
    features=[
        expanded_features,

        # Feature selection
        [trained.FeatureSelector(
            expanded_features,
            # use random forest's importance to trim
            selectors.RandomForestSelector(classifier=True),
            target=AsFactor('class'), # target to use
            n_keep=5, # keep top 5 features
            )],

        # Reduce feature dimension (pointless on this dataset)
        [combo.DimensionReduction(expanded_features,
                            decomposer=decomposition.PCA(n_components=4))],

        # Normalized features
        [Normalize(f) for f in expanded_features],
    ]
)

Status

Ramp is alpha currently, so expect bugs, bug fixes and API changes.

Requirements

• Numpy
• Scipy
• Pandas
• PyTables
• Sci-kit Learn
• gensim

Author

Ken Van Haren. Email with feedback/questions: [email protected] @squaredloss

Contributors

• John McDonnell
• Rob Story