julia/examples/mnist/lenet.jl

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using MXNet

#--------------------------------------------------------------------------------
# define lenet

# input
data = mx.Variable(:data)

# first conv
conv1 = @mx.chain mx.Convolution(data, kernel=(5,5), num_filter=20)  =>
                  mx.Activation(act_type=:tanh) =>
                  mx.Pooling(pool_type=:max, kernel=(2,2), stride=(2,2))

# second conv
conv2 = @mx.chain mx.Convolution(conv1, kernel=(5,5), num_filter=50) =>
                  mx.Activation(act_type=:tanh) =>
                  mx.Pooling(pool_type=:max, kernel=(2,2), stride=(2,2))

# first fully-connected
fc1   = @mx.chain mx.Flatten(conv2) =>
                  mx.FullyConnected(num_hidden=500) =>
                  mx.Activation(act_type=:tanh)

# second fully-connected
fc2   = mx.FullyConnected(fc1, num_hidden=10)

# softmax loss
lenet = mx.SoftmaxOutput(fc2, name=:softmax)


#--------------------------------------------------------------------------------
# load data
batch_size = 100
include("mnist-data.jl")
train_provider, eval_provider = get_mnist_providers(batch_size; flat=false)

#--------------------------------------------------------------------------------
# fit model
model = mx.FeedForward(lenet, context=mx.gpu())

# optimizer
optimizer = mx.SGD(η=0.05, μ=0.9, λ=0.00001)

# fit parameters
mx.fit(model, optimizer, train_provider, n_epoch=20, eval_data=eval_provider)