#791 – Matrix Multiplication, Part I – Rows and Columns

To understand how WPF transforms points, it’s useful to know how to multiply two matrices together.

You can multiply one matrix (A) by another matrix (B) if the number of columns in A equals the number of rows in B.  The resulting matrix has the same number of rows as matrix A and the same number of columns as matrix B.

That is–multiplying an m x n matrix by an n x p matrix yields an m x p matrix.

Note: When describing the dimensions of a matrix, the first number refers to the number of rows and the second number refers to the number of columns.

For  example:

  • Multiplying a 2 x 3 matrix by a 3 x 1 matrix yields a 2 x 1 matrix
  • Multiplying a 2 x 2 matrix by a 2 x 1 matrix yields a 2 x 1 matrix
  • Multiplying a 3 x 3 matrix by a 3 x 1 matrix yields a 3 x 1 matrix

791-001

 

About Sean
Software developer in the Twin Cities area, passionate about .NET technologies. Equally passionate about my own personal projects related to family history and preservation of family stories and photos.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: