NeuralProcesses 0.1.3

A framework for composing Neural Processes in Python

Neural Processes

A framework for composing Neural Processes in Python. See also NeuralProcesses.jl.

This package is currently under construction. There will be more here soon. In the meantime, see NeuralProcesses.jl.

Contents:

• Installation
• Examples of Predefined Models
• Build Your Own Model

Installation

See the instructions here. Then simply

pip install neuralprocesses

Examples of Predefined Models

TensorFlow

GNP

import lab as B
import tensorflow as tf

import neuralprocesses.tensorflow as nps

cnp = nps.construct_gnp(dim_x=2, dim_y=3, likelihood="lowrank")
dist = cnp(
    B.randn(tf.float32, 16, 2, 10),
    B.randn(tf.float32, 16, 3, 10),
    B.randn(tf.float32, 16, 2, 15),
)
mean, var = dist.mean, dist.var

print(dist.logpdf(B.randn(tf.float32, 16, 3, 15)))
print(dist.sample())
print(dist.kl(dist))
print(dist.entropy())

ConvGNP

import lab as B
import tensorflow as tf

import neuralprocesses.tensorflow as nps

cnp = nps.construct_convgnp(dim_x=2, dim_y=3, likelihood="lowrank")

dist = cnp(
    B.randn(tf.float32, 16, 2, 10),
    B.randn(tf.float32, 16, 3, 10),
    B.randn(tf.float32, 16, 2, 15),
)
mean, var = dist.mean, dist.var

print(dist.logpdf(B.randn(tf.float32, 16, 3, 15)))
print(dist.sample())
print(dist.kl(dist))
print(dist.entropy())

ConvGNP with Auxiliary Variables

import lab as B
import tensorflow as tf

import neuralprocesses.tensorflow as nps

cnp = nps.construct_convgnp(
    dim_x=2,
    dim_yc=(
        3,  # Observed data has three dimensions.
        1,  # First auxiliary variable has one dimension.
        2,  # Second auxiliary variable has two dimensions.
    ),
    dim_xt_aug=4,  # Third auxiliary variable has four dimensions.
    dim_yt=3,  # Predictions have three dimensions.
    num_basis_functions=64, 
    likelihood="lowrank",
)

observed_data = (
    B.randn(tf.float32, 16, 2, 10),
    B.randn(tf.float32, 16, 3, 10),
)

# Define three auxiliary variables. The first one is specified like the observed data
# at arbitrary inputs.
aux_var1 = (
    B.randn(tf.float32, 16, 2, 12),
    B.randn(tf.float32, 16, 1, 12),  # Has one dimension.
)
# The second one is specified on a grid.
aux_var2 = (
    (B.randn(tf.float32, 16, 1, 25), B.randn(tf.float32, 16, 1, 35)),
    B.randn(tf.float32, 16, 2, 25, 35),  # Has two dimensions.
)
# The third one is specific to the target inputs. We could encoder it like the first
# auxiliary variable `aux_var1`, but we illustrate how an MLP-style encoding can
# also be used. The number must match the number of target inputs!
aux_var3 = B.randn(tf.float32, 16, 4, 15)  # Has four dimensions.

dist = cnp(
    [observed_data, aux_var1, aux_var2],
    (B.randn(tf.float32, 16, 2, 15), aux_var3),
)
mean, var = dist.mean, dist.var

print(dist.logpdf(B.randn(tf.float32, 16, 3, 15)))
print(dist.sample())
print(dist.kl(dist))
print(dist.entropy())

PyTorch

GNP

import lab as B
import torch

import neuralprocesses.torch as nps

cnp = nps.construct_gnp(dim_x=2, dim_y=3, likelihood="lowrank")
dist = cnp(
    B.randn(torch.float32, 16, 2, 10),
    B.randn(torch.float32, 16, 3, 10),
    B.randn(torch.float32, 16, 2, 15),
)
mean, var = dist.mean, dist.var

print(dist.logpdf(B.randn(torch.float32, 16, 3, 15)))
print(dist.sample())
print(dist.kl(dist))
print(dist.entropy())

ConvGNP

import lab as B
import torch

import neuralprocesses.torch as nps

cnp = nps.construct_convgnp(dim_x=2, dim_y=3, likelihood="lowrank")
dist = cnp(
    B.randn(torch.float32, 16, 2, 10),
    B.randn(torch.float32, 16, 3, 10),
    B.randn(torch.float32, 16, 2, 15),
)
mean, var = dist.mean, dist.var

print(dist.logpdf(B.randn(torch.float32, 16, 3, 15)))
print(dist.sample())
print(dist.kl(dist))
print(dist.entropy())

Build Your Own Model

ConvGNP

TensorFlow

import lab as B
import tensorflow as tf

import neuralprocesses.tensorflow as nps

dim_x = 1
dim_y = 1

# CNN architecture:
unet = nps.UNet(
    dim=dim_x,
    in_channels=2 * dim_y,
    out_channels=(2 + 512) * dim_y,
    channels=(8, 16, 16, 32, 32, 64),
)

# Discretisation of the functional embedding:
disc = nps.Discretisation(
    points_per_unit=64,
    multiple=2**unet.num_halving_layers,
    margin=0.1,
    dim=dim_x,
)

# Create the encoder and decoder and construct the model.
encoder = nps.FunctionalCoder(
    disc,
    nps.Chain(
        nps.PrependDensityChannel(),
        nps.SetConv(scale=2 / disc.points_per_unit),
        nps.DivideByFirstChannel(),
    ),
)
decoder = nps.Chain(
    unet,
    nps.SetConv(scale=2 / disc.points_per_unit),
    nps.LowRankGaussianLikelihood(512),
)
convgnp = nps.Model(encoder, decoder)

# Run the model on some random data.
dist = convgnp(
    B.randn(tf.float32, 16, 1, 10),
    B.randn(tf.float32, 16, 1, 10),
    B.randn(tf.float32, 16, 1, 15),
)