Machine Learning for Finance

Tensors and the computational graph

Tensors are arrays of numbers that transform based on specific rules. The simplest kind of tensor is a single number. This is also called a scalar. Scalars are sometimes referred to as rank-zero tensors.

The next tensor is a vector, also known as a rank-one tensor. The next The next ones up the order are matrices, called rank-two tensors; cube matrices, called rank-three tensors; and so on. You can see the rankings in the following table:

Rank	Name	Expresses
0	Scalar	Magnitude
1	Vector	Magnitude and Direction
2	Matrix	Table of numbers
3	Cube Matrix	Cube of numbers
n	n-dimensional matrix	You get the idea

This book mostly uses the word tensor for rank-three or higher tensors.

TensorFlow and every ...