archena

%load_ext autoreload
%autoreload 2
import sys
sys.path.append("../")
import components.data
import components.features
import components.training

archena

def fit(train_X, train_y):
    rf_model = RandomForestRegressor(random_state=1, n_estimators=10)
    rf_model.fit(train_X, train_y)
    return rf_model

def validate(model, val_X, val_y):
    rf_val_predictions = model.predict(val_X)
    return mean_absolute_error(rf_val_predictions, val_y)

rf_model = fit(train_X, train_y)

archena

rf_model = RandomForestRegressor(random_state=1, n_estimators=10)
rf_model.fit(train_X, train_y)
rf_val_predictions = rf_model.predict(val_X)
rf_val_mae = mean_absolute_error(rf_val_predictions, val_y)

print("Validation MAE for Random Forest Model: {:,.0f}".format(rf_val_mae))

archena

/**
 * We can't write 'new T()' in Java, and it wouldn't be typesafe if we could. Some people blame type erasure for this, but
 * the real problem is that we haven't specified that T has a zero-argument constructor, we just assumed it.
 * To do it properly, encode the constructors through generics. No runtime type information needed...
 */

    interface Constructor0<T> {
        T make();
    }

archena

boolean r = isOrdered(Arrays.asList(1, 3, 5, 7));  // true
boolean r2 = isOrdered(Arrays.asList(1, 5, 5, 7)); // false
boolean r3 = isOrdered(Arrays.asList(5, 3, 6, 7)); // false

public static <T extends Comparable<T>> boolean isOrdered(Collection<T> collection) {
    final Iterator<T> i = collection.iterator();
    final Iterator<T> j = collection.iterator();
    j.next();

    while(j.hasNext())

archena

def loopA = {
  // 0 1 2 3
  var i = 0
  while(i < 4) {
    print(i)
    i = i + 1
  }
  println("")
}

archena

interface Semigroup<T> {
    T apply(T a, T b);
}

interface Monoid<T> extends Semigroup<T> {
    T identity();
}

interface Group<T> extends Monoid<T> {
    T inverse(T a);

archena

class ReifiableType<T> {
    final T value;
    final Class<T> type;

    public ReifiableType(T value, Class<T> type) {
        this.value = value;
        this.type = type;
    }
}

archena

import java.util.Iterator;

class GeneratorTest {
    public static void main(String[] args) {
        /**
         * A generator for Fibonacci numbers
         */
        Generator<Integer> g = new Generator<>(new Sequencer<Integer>() {
                private int a = 1, b = 1;
                public Integer get() {