# Understand Vector Dot Product: A Beginner Introduction – Machine Learning Tutorial

By | October 11, 2020

Vector dot product is widely used in machine learning. In this tutorial, we will introduce it for machine learning beginners.

## What is vector dot product?

Given two vectors A and B, the dot product between them are defined as:

We can find the result of two vector dot product is a scalar.

## The difference between vector dot product and element-wise multiplication

Vector dot product is different from element-wise multiplication, the  element-wise multiplication (product) can be defined as:

Understand Element-wise Multiplication Between Two Vector – Machine Learning Tutorial

From above, we can find:

dot product(A, B) = sum(element-wise multiplication(A, B))

## How to calculate the vector dot product?

In tensorflow:

We can use tf.tensordot() function to compute.

In numpy:

We can use numpy.dot() to compute.

Calculate Dot Product of Two Vectors in Numpy for Beginners – Numpy Tutorial