pytorch/caffe2/python/layers/random_fourier_features.py
Jacqueline Xu 8cedf35d55 Adding Random Fourier Features to SparseNN Model and Flow
Summary:
- Integrated RFF into the preprocessing workflow for dense features
- Developed Flow interface to input RFF parameters
- Created unit test for using RFF with sparseNN

Reviewed By: chocjy

Differential Revision: D5367534

fbshipit-source-id: 07307259c501a614d9ee68a731f0cc8ecd17db68
2017-07-07 09:39:32 -07:00

95 lines
3.5 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
from caffe2.python import core, schema
from caffe2.python.layers.layers import (
ModelLayer,
LayerParameter
)
import numpy as np
class RandomFourierFeatures(ModelLayer):
def __init__(
self,
model,
input_record,
output_dims,
sigma, # bandwidth
w_init=None,
b_init=None,
name='random_fourier_features',
**kwargs):
super(RandomFourierFeatures, self).__init__(model, name, input_record,
**kwargs)
assert isinstance(input_record, schema.Scalar), "Incorrect input type"
input_dims = input_record.field_type().shape[0]
assert input_dims >= 1, "Expected input dimensions >= 1, got %s" \
% input_dims
self.output_dims = output_dims
assert self.output_dims >= 1, "Expected output dimensions >= 1, got %s" \
% self.output_dims
self.output_schema = schema.Scalar(
(np.float32, (self.output_dims, )),
model.net.NextScopedBlob(name + '_output')
)
assert sigma > 0.0, "Expected bandwidth > 0, got %s" % sigma
# Initialize train_init_net parameters
w_init = w_init if w_init else (
'GaussianFill', {'mean': 0.0, 'std': 1.0 / sigma}
)
b_init = b_init if b_init else (
'UniformFill', {'min': 0.0, 'max': 2 * np.pi}
)
self.w = model.net.NextScopedBlob(name + "_w")
self.b = model.net.NextScopedBlob(name + "_b")
self.params.append(
LayerParameter(
parameter=self.w,
initializer=core.CreateOperator(w_init[0],
[],
self.w,
shape=(input_dims, self.output_dims),
**w_init[1]
),
optimizer=model.NoOptim))
self.params.append(
LayerParameter(
parameter=self.b,
initializer=core.CreateOperator(b_init[0],
[],
self.b,
shape=[self.output_dims],
**b_init[1]
),
optimizer=model.NoOptim))
def add_ops(self, net):
# Matrix multiplication for input and w
weighted_term = net.MatMul(self.input_record.field_blobs() + [self.w],
net.NextScopedBlob('weighted_term'))
# Add wx + b
cosine_arg = net.Add([weighted_term, self.b],
net.NextScopedBlob('cosine_arg'),
broadcast=1, axis=1)
# Apply cosine to new vectors
new_feature_vec = net.Cos([cosine_arg],
net.NextScopedBlob('new_feature_vec'))
# Multiply each element in vector by sqrt(2/D)
scale = np.sqrt(2.0 / self.output_dims)
net.Scale([new_feature_vec],
self.output_schema.field_blobs(),
scale=scale)