A wrapper around TensorFlow, a popular open source machine learning framework from Google.

Documentation available here.

See a list of advantages over the Python API.

See NEWS.

using TensorFlow

sess = TensorFlow.Session()

x = TensorFlow.constant(Float64[1,2])
y = TensorFlow.Variable(Float64[3,4])
z = TensorFlow.placeholder(Float64)

w = exp(x + z + -y)

run(sess, TensorFlow.global_variables_initializer())
res = run(sess, w, Dict(z=>Float64[1,2]))
Base.Test.@test res[1] ≈ exp(-1)

Install via

Pkg.add("TensorFlow")

To enable support for GPU usage (Linux only), set an environment variable TF_USE_GPU to "1" and then rebuild the package. eg

ENV["TF_USE_GPU"] = "1"
Pkg.build("TensorFlow")

CUDA 8.0 and cudnn are required for GPU usage. If you need to use a different version of CUDA you can compile libtensorflow from source.

Simply run docker run -it malmaud/julia:tf to open a Julia REPL that already has TensorFlow installed:

julia> using TensorFlow
julia>

For a version of TensorFlow.jl that utilizes GPUs, use nvidia-docker run -it malmaud/julia:tf_gpu. Download nvidia-docker if you don't already have it.

Realistic demonstration of using variable scopes and advanced optimizers

using Distributions

# Generate some synthetic data
x = randn(100, 50)
w = randn(50, 10)
y_prob = exp(x*w)
y_prob ./= sum(y_prob,2)

function draw(probs)
    y = zeros(size(probs))
    for i in 1:size(probs, 1)
        idx = rand(Categorical(probs[i, :]))
        y[i, idx] = 1
    end
    return y
end

y = draw(y_prob)

# Build the model
sess = Session(Graph())
X = placeholder(Float64)
Y_obs = placeholder(Float64)

variable_scope("logistic_model", initializer=Normal(0, .001)) do
    global W = get_variable("weights", [50, 10], Float64)
    global B = get_variable("bias", [10], Float64)
end

Y=nn.softmax(X*W + B)
Loss = -reduce_sum(log(Y).*Y_obs)
optimizer = train.AdamOptimizer()
minimize_op = train.minimize(optimizer, Loss)
saver = train.Saver()
# Run training
run(sess, global_variables_initializer())
checkpoint_path = mktempdir()
info("Checkpoint files saved in $checkpoint_path")
for epoch in 1:100
    cur_loss, _ = run(sess, vcat(Loss, minimize_op), Dict(X=>x, Y_obs=>y))
    println(@sprintf("Current loss is %.2f.", cur_loss))
    train.save(saver, sess, joinpath(checkpoint_path, "logistic"), global_step=epoch)
end

If you see issues from the ccall or python interop, try updating TensorFlow both in Julia and in the global python install:

julia> Pkg.build("TensorFlow")

$ pip install --upgrade tensorflow

If you already have a version of libtensorflow.so or libtensorflow.dylib that you would like to use, you can set the environment variable LIBTENSORFLOW to its path. By default, TensorFlow.jl will use the library in TensorFlow.jl/deps/usr/bin.

If you want to build your own version of the TensorFlow binary library instead of relying on the one that is installed with Pkg.build("TensorFlow"), follow the instructions from https://www.tensorflow.org/install/install_sources, except:

• In the section "Build the pip package", instead run bazel build --config=opt //tensorflow:libtensorflow.so.
• Then copy the file "bazel-bin/tensorflow/libtensorflow.so" to the "deps/usr/bin" directory in the TensorFlow.jl package.
• On OS X, rename the file to libtensorflow.dylib.

A convenience script is included to use Docker to easily build the library. Just install docker and run julia build_libtensorflow.so from the "deps" directory of the TensorFlow.jl package.