07. Matrix Multiplication: Part 2

Important Reminders About Matrix Multiplication

• The number of columns in the left matrix must equal the number of rows in the right matrix.
• The answer matrix always has the same number of rows as the left matrix and the same number of columns as the right matrix.
• Order matters . Multiplying A•B is not the same as multiplying B•A .
• Data in the left matrix should be arranged as rows ., while data in the right matrix should be arranged as columns .

If you keep these four points in mind, you should always be able to figure out how to properly arrange your matrix multiplications when building a neural network.