Combine
This sample calculates the dot product of two integer vectors. It uses a user-created sequence operator, Combine, to calculate the dot product, passing it a lambda function to multiply two arrays, element by element, and sum the result.
public static class CustomSequenceOperators
{
public static IEnumerable Combine(this IEnumerable first, IEnumerable second,
Func func) {
using (IEnumerator e1 = first.GetEnumerator(), e2 = second.GetEnumerator())
{
while (e1.MoveNext() && e2.MoveNext()) {
yield return func(e1.Current, e2.Current);
}
}
}
}
public void Linq98() {
int[] vectorA = { 0, 2, 4, 5, 6 };
int[] vectorB = { 1, 3, 5, 7, 8 };
int dotProduct = vectorA.Combine(vectorB, (a, b) => a * b).Sum();
Console.WriteLine("Dot product: {0}", dotProduct);
}
Result
Dot product: 109