Model

A Model is the simplest way to build, train, and evaluate neural networks in etch. The Model type takes care of the underlying implementation details for Graph, DataLoader, and Optimiser.

There are three types of Model.

• Sequential: trains a computational graph to predict either continuous variables or classes, and allows more control over the layers of the network.
• Regressor: trains a computational graph to predict continuous variables. For example, what will be the future price of a particular currency?
• Classifier: trains a computational graph to predict classes. For example, is this a picture of a cat or a dog?

Construct a Model

Create a Model by setting a flag in the constructor.

function main()

    var model1 = Model("sequential");
    var model2 = Model("regressor");
    var model3 = Model("classifier");

endfunction

Add

Manually add the layers to a sequential Model.

The function add(x, y, z, a) with four parameters requires you specify a flag type, the dimensions, and the activation type.

The function add(x, y, z) with three parameters requires you specify a flag type and the dimensions.

function main()

    var model = Model("sequential");
    model.add("dense", 10u64, 10u64, "relu");         
    model.add("dense", 10u64, 10u64, "relu");      
    model.add("dense", 10u64, 1u64);

endfunction

Compile

Compile the Model with the compile() function.

The function compile(loss-function-flag, optimiser-flag) takes two inputs. In the below example, we compiled with a mean squared error loss function and an Adam Optimiser.

function main()

    var model = Model("sequential");
    model.add("dense", 10u64, 10u64, "relu");         
    model.add("dense", 10u64, 10u64, "relu");      
    model.add("dense", 10u64, 1u64);

    model.compile("mse", "adam");

endfunction

Read in input data

The readCSV(System.Argv(1)) function allows you to read in data from csv files with the etch compiler argument commands.

For example, run the below script with the following command. The first if-else block ensure the correct number of arguments with System.Argc().

./etch -- file1 file2 file3 file4

function main()

    if (System.Argc() != 5)
      print("Usage: SCRIPT_FILE -- PATH/TO/BOSTON_TRAIN_DATA.CSV PATH/TO/BOSTON_TRAIN_LABELS.CSV PATH/TO/BOSTON_TEST_DATA.CSV PATH/TO/BOSTON_TEST_LABELS.CSV ");
      return;
    endif

    var data = readCSV(System.Argv(1));
    var label = readCSV(System.Argv(2));
    var test_data = readCSV(System.Argv(3));
    var test_label = readCSV(System.Argv(4));

endfunction

Fit

With the Model set up as above, you can now add the input data and run the training function fit(data, labels, batch-size).

function main()

    var data = readCSV(System.Argv(1));
    var label = readCSV(System.Argv(2));
    var test_data = readCSV(System.Argv(3));
    var test_label = readCSV(System.Argv(4));

    var model = Model("sequential");
    model.add("dense", 13u64, 10u64, "relu");
    model.add("dense", 10u64, 10u64, "relu");
    model.add("dense", 10u64, 1u64);
    model.compile("mse", "adam");

    var batch_size = 10u64;
    model.fit(data, label, batch_size);

endfunction

Evaluate

Evaluate the prediction error with the evaluate() function.

function main()

    var data = readCSV(System.Argv(1));
    var label = readCSV(System.Argv(2));
    var test_data = readCSV(System.Argv(3));
    var test_label = readCSV(System.Argv(4));

    var model = Model("sequential");
    model.add("dense", 13u64, 10u64, "relu");
    model.add("dense", 10u64, 10u64, "relu");
    model.add("dense", 10u64, 1u64);
    model.compile("mse", "adam");

    var batch_size = 10u64;
    model.fit(data, label, batch_size);

    var loss = model.evaluate();
    printLn(loss);

endfunction

Predict

Finally, make predictions on the data

function main()

    var data = readCSV(System.Argv(1));
    var label = readCSV(System.Argv(2));
    var test_data = readCSV(System.Argv(3));
    var test_label = readCSV(System.Argv(4));

    var model = Model("sequential");
    model.add("dense", 13u64, 10u64, "relu");
    model.add("dense", 10u64, 10u64, "relu");
    model.add("dense", 10u64, 1u64);
    model.compile("mse", "adam");

    var batch_size = 10u64;
    model.fit(data, label, batch_size);

    var loss = model.evaluate();
    printLn(loss);

    var predictions = model.predict(test_data);
    print(predictions.at(0u64, 0u64));

endfunction