May 30, 2023

Excel & Google Sheets: Formula Guides

Hey there, fellow spreadsheet enthusiasts! Today, we're going to dive deep into one of my favorite Google Sheets formulas: MMULT. Sure, it might not have the most exciting name, but let me tell you, it's a game-changer.

First things first, let's break down what MMULT actually does. MMULT stands for "matrix multiplication", which basically means it's a formula that multiplies two matrices together to produce a third matrix. Okay, that might sound a bit complicated, but trust me, it's not as intimidating as it seems.

Let's say you have two matrices, A and B. Matrix A has dimensions of m x n, while matrix B has dimensions of n x p. When you multiply these two matrices together using MMULT, you end up with a new matrix of dimensions m x p. The formula looks like this:

=MMULT(A, B)

Don't worry too much about the specifics of the formula -- all you really need to know is that it takes two matrices as inputs and produces a new matrix as output.

So, why should you care about MMULT? Well, for one, it can save you a ton of time and effort when working with complex data sets. Let's say you have a table of data with hundreds or even thousands of rows and columns. Normally, if you wanted to perform calculations on that data, you'd have to write out each formula row by row, column by column. But with MMULT, you can perform those calculations on entire matrices at once.

Another benefit of MMULT is that it allows you to perform matrix operations that simply aren't possible with other formulas. For example, you can use MMULT to find the inverse of a matrix, or to solve systems of linear equations. These might sound like advanced techniques, but they can be incredibly helpful in certain situations, such as when you're working with financial data or modeling complex systems.

Let's say you have a table of sales data that looks something like this:

Month | Product 1 | Product 2 | Product 3 |
---|---|---|---|

Jan | 100 | 200 | 150 |

Feb | 150 | 175 | 225 |

Mar | 175 | 125 | 250 |

To find the total sales for each product, you could use the SUM function, like so:

=SUM(B2:B4)

However, if you have a lot of products, this could get tedious really fast. Instead, you could use MMULT like this:

=MMULT(B2:D4, TRANSPOSE(COLUMN(B1:D1)^0))

Don't worry too much about the specifics of this formula -- just know that it allows you to find the sum of each column in one go. Pretty cool, right?

Now, let's say you have a different kind of data set. You have a matrix of values, and you need to find the inverse of that matrix. This might sound complicated, but with MMULT, it's actually pretty straightforward.

Here's the formula you'd use:

=MMULT(A1:B2, MINVERSE(A1:B2))

Again, don't worry too much about the specifics of the formula -- just know that it allows you to find the inverse of a matrix with just one formula.

So there you have it, folks -- MMULT in all its matrix-multiplying glory. Hopefully this article has helped you understand the power and usefulness of this formula. And who knows, maybe you'll even find yourself using it on a daily basis!