~/tedtes/writing/math-foundations-for-reasoning-models

~/writing/math-foundations-for-reasoning-models $ ls

Matrices as Transformations

Matrix

A matrix is a rectangular arrangement of numbers organized by rows and columns.

~/writing/math-foundations-for-reasoning-models $ cat topic.md

Matrix

Definition

A matrix is a rectangular arrangement of numbers.

Example:

[1 2 3]
[4 5 6]

This matrix has:

2 rows
3 columns

Matrix = numbers arranged in rows and columns.


Rows And Columns

Rows go across.

Columns go down.

Example:

[1 2 3]
[4 5 6]

Rows:

[1 2 3]
[4 5 6]

Columns:

[1]
[4]

[2]
[5]

[3]
[6]

A matrix organizes numbers in two directions: row direction and column direction.


Matrix Shape

The shape of a matrix is:

number of rows x number of columns

Example:

[1 2 3]
[4 5 6]

has shape:

2 x 3

Another example:

[1 2]
[3 4]
[5 6]

has shape:

3 x 2

Matrix shape tells how many rows and columns it has.


Matrix Entries

Each number in a matrix is an entry.

Example:

[1 2]
[3 4]

Entries:

1, 2, 3, 4

Each entry has a row position and a column position.

Example:

entry at row 1, column 2 = 2
entry at row 2, column 1 = 3

A matrix entry is a value located by row and column.


Matrix vs Vector

A vector is one ordered line of values.

Example:

[2, 4, 6]

A matrix has rows and columns.

Example:

[1 2 3]
[4 5 6]

A vector has one main direction of organization.

A matrix has two.

A matrix extends vector structure from one direction to rows and columns.


Matrix As Structured Object

A matrix is not just a pile of numbers.

Its structure matters.

Example:

[1 2]
[3 4]

is different from:

[1 3]
[2 4]

The same entries are arranged differently.

That changes what the matrix does.

Matrix meaning depends on both values and arrangement.


Why Matrices Matter

Matrices matter because they can represent:

  • structured data
  • systems of values
  • transformations of vectors
  • relationships between components

The key idea for this chapter:

matrix acts on vector -> new vector

Matrices are structured numerical objects that can organize and transform vector data.


Final Summary

  • A matrix is a rectangular arrangement of numbers.
  • It has rows and columns.
  • Its shape is rows x columns.
  • Each entry has a row and column position.
  • A matrix extends vector structure.
  • Arrangement matters.
  • Matrices can store data or represent transformations.

~/writing/math-foundations-for-reasoning-models $ open

Continue the series.

Matrix as Data Structure