diff --git a/latest/contributing.html b/latest/contributing.html index 8d05506d..3093cfa2 100644 --- a/latest/contributing.html +++ b/latest/contributing.html @@ -6,4 +6,4 @@ m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) ga('create', 'UA-36890222-9', 'auto'); ga('send', 'pageview'); -

Contributing & Help

Contributing & Help

If you need help, please ask on the Julia forum, the slack (channel #machine-learning), or Flux's Gitter.

Right now, the best way to help out is to try out the examples and report any issues or missing features as you find them. The second best way is to help us spread the word, perhaps by starring the repo.

If you're interested in hacking on Flux, most of the code is pretty straightforward. Adding new layer definitions or cost functions is simple using the Flux DSL itself, and things like data utilities and training processes are all plain Julia code.

If you get stuck or need anything, let us know!

+

Contributing & Help

Contributing & Help

If you need help, please ask on the Julia forum, the slack (channel #machine-learning), or Flux's Gitter.

Right now, the best way to help out is to try out the examples and report any issues or missing features as you find them. The second best way is to help us spread the word, perhaps by starring the repo.

If you're interested in hacking on Flux, most of the code is pretty straightforward. Adding new layer definitions or cost functions is simple using the Flux DSL itself, and things like data utilities and training processes are all plain Julia code.

If you get stuck or need anything, let us know!

diff --git a/latest/data/onehot.html b/latest/data/onehot.html index d31bf049..677eafcf 100644 --- a/latest/data/onehot.html +++ b/latest/data/onehot.html @@ -6,7 +6,7 @@ m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) ga('create', 'UA-36890222-9', 'auto'); ga('send', 'pageview'); -

One-Hot Encoding

One-Hot Encoding

It's common to encode categorical variables (like true, false or cat, dog) in "one-of-k" or "one-hot" form. Flux provides the onehot function to make this easy.

julia> using Flux: onehot
+

One-Hot Encoding

One-Hot Encoding

It's common to encode categorical variables (like true, false or cat, dog) in "one-of-k" or "one-hot" form. Flux provides the onehot function to make this easy.

julia> using Flux: onehot
 
 julia> onehot(:b, [:a, :b, :c])
 3-element Flux.OneHotVector:
@@ -37,4 +37,4 @@ julia> onecold(ans, [:a, :b, :c])
 3-element Array{Symbol,1}:
   :b
   :a
-  :b

Note that these operations returned OneHotVector and OneHotMatrix rather than Arrays. OneHotVectors behave like normal vectors but avoid any unnecessary cost compared to using an integer index directly.. For example, multiplying a matrix with a one-hot vector simply slices out the relevant row of the matrix under the hood.

+ :b

Note that these operations returned OneHotVector and OneHotMatrix rather than Arrays. OneHotVectors behave like normal vectors but avoid any unnecessary cost compared to using an integer index directly. For example, multiplying a matrix with a one-hot vector simply slices out the relevant row of the matrix under the hood.

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Home

Flux: The Julia Machine Learning Library

Flux is a library for machine learning. It comes "batteries-included" with many useful tools built in, but also lets you use the full power of the Julia language where you need it. The whole stack is implemented in clean Julia code (right down to the GPU kernels) and any part can be tweaked to your liking.

Installation

Install Julia 0.6.0 or later, if you haven't already.

Pkg.add("Flux")
+

Home

Flux: The Julia Machine Learning Library

Flux is a library for machine learning. It comes "batteries-included" with many useful tools built in, but also lets you use the full power of the Julia language where you need it. The whole stack is implemented in clean Julia code (right down to the GPU kernels) and any part can be tweaked to your liking.

Installation

Install Julia 0.6.0 or later, if you haven't already.

Pkg.add("Flux")
 Pkg.test("Flux") # Check things installed correctly

Start with the basics. The model zoo is also a good starting point for many common kinds of models.

diff --git a/latest/models/basics.html b/latest/models/basics.html index 83275958..598a62ca 100644 --- a/latest/models/basics.html +++ b/latest/models/basics.html @@ -6,7 +6,7 @@ m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) ga('create', 'UA-36890222-9', 'auto'); ga('send', 'pageview'); -

Basics

Model-Building Basics

Taking Gradients

Consider a simple linear regression, which tries to predict an output array y from an input x. (It's a good idea to follow this example in the Julia repl.)

W = rand(2, 5)
+

Basics

Model-Building Basics

Taking Gradients

Consider a simple linear regression, which tries to predict an output array y from an input x. (It's a good idea to follow this example in the Julia repl.)

W = rand(2, 5)
 b = rand(2)
 
 predict(x) = W*x .+ b
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index ba07c630..cd69d54e 100644
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Layer Reference

Model Layers

Flux.ChainType.
Chain(layers...)

Chain multiple layers / functions together, so that they are called in sequence on a given input.

m = Chain(x -> x^2, x -> x+1)
+

Layer Reference

Model Layers

Flux.ChainType.
Chain(layers...)

Chain multiple layers / functions together, so that they are called in sequence on a given input.

m = Chain(x -> x^2, x -> x+1)
 m(5) == 26
 
 m = Chain(Dense(10, 5), Dense(5, 2))
 x = rand(10)
-m(x) == m[2](m[1](x))

Chain also supports indexing and slicing, e.g. m[2] or m[1:end-1]. m[1:3](x) will calculate the output of the first three layers.

source
Flux.DenseType.
Dense(in::Integer, out::Integer, σ = identity)

Creates a traditional Dense layer with parameters W and b.

y = σ.(W * x .+ b)

The input x must be a vector of length in, or a batch of vectors represented as an in × N matrix. The out y will be a vector or batch of length in.

source
+m(x) == m[2](m[1](x))

Chain also supports indexing and slicing, e.g. m[2] or m[1:end-1]. m[1:3](x) will calculate the output of the first three layers.

source
Flux.DenseType.
Dense(in::Integer, out::Integer, σ = identity)

Creates a traditional Dense layer with parameters W and b.

y = σ.(W * x .+ b)

The input x must be a vector of length in, or a batch of vectors represented as an in × N matrix. The out y will be a vector or batch of length in.

source
diff --git a/latest/models/recurrence.html b/latest/models/recurrence.html index 880095fe..cc82ac10 100644 --- a/latest/models/recurrence.html +++ b/latest/models/recurrence.html @@ -6,7 +6,7 @@ m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) ga('create', 'UA-36890222-9', 'auto'); ga('send', 'pageview'); -

Recurrence

Recurrent Models

Recurrent Cells

In the simple feedforward case, our model m is a simple function from various inputs xᵢ to predictions yᵢ. (For example, each x might be an MNIST digit and each y a digit label.) Each prediction is completely independent of any others, and using the same x will always produce the same y.

y₁ = f(x₁)
+

Recurrence

Recurrent Models

Recurrent Cells

In the simple feedforward case, our model m is a simple function from various inputs xᵢ to predictions yᵢ. (For example, each x might be an MNIST digit and each y a digit label.) Each prediction is completely independent of any others, and using the same x will always produce the same y.

y₁ = f(x₁)
 y₂ = f(x₂)
 y₃ = f(x₃)
 # ...

Recurrent networks introduce a hidden state that gets carried over each time we run the model. The model now takes the old h as an input, and produces a new h as output, each time we run it.

h = # ... initial state ...
@@ -38,6 +38,5 @@ h = rand(5)
 m = Flux.Recur(rnn, h)
 
 y = m(x)

The Recur wrapper stores the state between runs in the m.state field.

If you use the RNN(10, 5) constructor – as opposed to RNNCell – you'll see that it's simply a wrapped cell.

julia> RNN(10, 5)
-Recur(RNNCell(Dense(15, 5)))

Sequences

Often we want to work with sequences of inputs, rather than individual xs.

seq = [rand(10) for i = 1:10]

With Recur, applying our model to each element of a sequence is trivial:

map(m, seq) # returns a list of 5-element vectors

To make this a bit more convenient, Flux has the Seq type. This is just a list, but tagged so that we know it's meant to be used as a sequence of data points.

seq = Seq([rand(10) for i = 1:10])
-m(seq) # returns a new Seq of length 10

When we apply the model m to a seq, it gets mapped over every item in the sequence in order. This is just like the code above, but often more convenient.

You can get this behaviour more generally with the Over wrapper.

m = Over(Dense(10,5))
-m(seq) # returns a new Seq of length 10

Truncating Gradients

By default, calculating the gradients in a recurrent layer involves the entire history. For example, if we call the model on 100 inputs, calling back! will calculate the gradient for those 100 calls. If we then calculate another 10 inputs we have to calculate 110 gradients – this accumulates and quickly becomes expensive.

To avoid this we can truncate the gradient calculation, forgetting the history.

truncate!(m)

Calling truncate! wipes the slate clean, so we can call the model with more inputs without building up an expensive gradient computation.

+Recur(RNNCell(Dense(15, 5)))

Sequences

Often we want to work with sequences of inputs, rather than individual xs.

seq = [rand(10) for i = 1:10]

With Recur, applying our model to each element of a sequence is trivial:

m.(seq) # returns a list of 5-element vectors

This works even when we've chain recurrent layers into a larger model.

m = Chain(LSTM(10, 15), Dense(15, 5))
+m.(seq)

Truncating Gradients

By default, calculating the gradients in a recurrent layer involves the entire history. For example, if we call the model on 100 inputs, calling back! will calculate the gradient for those 100 calls. If we then calculate another 10 inputs we have to calculate 110 gradients – this accumulates and quickly becomes expensive.

To avoid this we can truncate the gradient calculation, forgetting the history.

truncate!(m)

Calling truncate! wipes the slate clean, so we can call the model with more inputs without building up an expensive gradient computation.

diff --git a/latest/search_index.js b/latest/search_index.js index b688d75a..0cc67fac 100644 --- a/latest/search_index.js +++ b/latest/search_index.js @@ -101,7 +101,7 @@ var documenterSearchIndex = {"docs": [ "page": "Recurrence", "title": "Sequences", "category": "section", - "text": "Often we want to work with sequences of inputs, rather than individual xs.seq = [rand(10) for i = 1:10]With Recur, applying our model to each element of a sequence is trivial:map(m, seq) # returns a list of 5-element vectorsTo make this a bit more convenient, Flux has the Seq type. This is just a list, but tagged so that we know it's meant to be used as a sequence of data points.seq = Seq([rand(10) for i = 1:10])\nm(seq) # returns a new Seq of length 10When we apply the model m to a seq, it gets mapped over every item in the sequence in order. This is just like the code above, but often more convenient.You can get this behaviour more generally with the Over wrapper.m = Over(Dense(10,5))\nm(seq) # returns a new Seq of length 10" + "text": "Often we want to work with sequences of inputs, rather than individual xs.seq = [rand(10) for i = 1:10]With Recur, applying our model to each element of a sequence is trivial:m.(seq) # returns a list of 5-element vectorsThis works even when we've chain recurrent layers into a larger model.m = Chain(LSTM(10, 15), Dense(15, 5))\nm.(seq)" }, { @@ -213,7 +213,7 @@ var documenterSearchIndex = {"docs": [ "page": "One-Hot Encoding", "title": "Batches", "category": "section", - "text": "onehotbatch creates a batch (matrix) of one-hot vectors, and argmax treats matrices as batches.julia> using Flux: onehotbatch\n\njulia> onehotbatch([:b, :a, :b], [:a, :b, :c])\n3×3 Flux.OneHotMatrix:\n false true false\n true false true\n false false false\n\njulia> onecold(ans, [:a, :b, :c])\n3-element Array{Symbol,1}:\n :b\n :a\n :bNote that these operations returned OneHotVector and OneHotMatrix rather than Arrays. OneHotVectors behave like normal vectors but avoid any unnecessary cost compared to using an integer index directly.. For example, multiplying a matrix with a one-hot vector simply slices out the relevant row of the matrix under the hood." + "text": "onehotbatch creates a batch (matrix) of one-hot vectors, and argmax treats matrices as batches.julia> using Flux: onehotbatch\n\njulia> onehotbatch([:b, :a, :b], [:a, :b, :c])\n3×3 Flux.OneHotMatrix:\n false true false\n true false true\n false false false\n\njulia> onecold(ans, [:a, :b, :c])\n3-element Array{Symbol,1}:\n :b\n :a\n :bNote that these operations returned OneHotVector and OneHotMatrix rather than Arrays. OneHotVectors behave like normal vectors but avoid any unnecessary cost compared to using an integer index directly. For example, multiplying a matrix with a one-hot vector simply slices out the relevant row of the matrix under the hood." }, { diff --git a/latest/training/optimisers.html b/latest/training/optimisers.html index 058c851f..f7c37ab8 100644 --- a/latest/training/optimisers.html +++ b/latest/training/optimisers.html @@ -6,7 +6,7 @@ m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) ga('create', 'UA-36890222-9', 'auto'); ga('send', 'pageview'); -

Optimisers

Optimisers

Consider a simple linear regression. We create some dummy data, calculate a loss, and backpropagate to calculate gradients for the parameters W and b.

W = param(rand(2, 5))
+

Optimisers

Optimisers

Consider a simple linear regression. We create some dummy data, calculate a loss, and backpropagate to calculate gradients for the parameters W and b.

W = param(rand(2, 5))
 b = param(rand(2))
 
 predict(x) = W*x .+ b
diff --git a/latest/training/training.html b/latest/training/training.html
index bd516d07..a97b8b48 100644
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Training

Training

To actually train a model we need three things:

  • A loss function, that evaluates how well a model is doing given some input data.

  • A collection of data points that will be provided to the loss function.

  • An optimiser that will update the model parameters appropriately.

With these we can call Flux.train!:

Flux.train!(loss, data, opt)

There are plenty of examples in the model zoo.

Loss Functions

The loss that we defined in basics is completely valid for training. We can also define a loss in terms of some model:

m = Chain(
+

Training

Training

To actually train a model we need three things:

  • A loss function, that evaluates how well a model is doing given some input data.

  • A collection of data points that will be provided to the loss function.

  • An optimiser that will update the model parameters appropriately.

With these we can call Flux.train!:

Flux.train!(loss, data, opt)

There are plenty of examples in the model zoo.

Loss Functions

The loss that we defined in basics is completely valid for training. We can also define a loss in terms of some model:

m = Chain(
   Dense(784, 32, σ),
   Dense(32, 10), softmax)