Gain dimension failure ending in error

2 views (last 30 days)
At first, I built the following control circle:
Gain window
As you can see x is a (4,1)-vector and in the picture below you can see G is a (1,4)-Matrix.
Multiplying a K.*u means G.*x means in dimensions: (1,4)*(4,1)=(1,1). But (however) a (4,4)-matrix is the solution, which leads to an error, cos I cant add 4,4 and a scalar. So why is (4,4) the solution or what did I miss in the gain window? (I set element wise multiplication K.*u)
  1 Comment
Lennart
Lennart on 12 Jun 2024
Edited: Lennart on 12 Jun 2024
Sorry I got it myself... I have to set Matrix(K*u) in the G window, so (1,4)*(4,1)=(1,1) and it does what it should do.

Sign in to comment.

Accepted Answer

Aquatris
Aquatris on 12 Jun 2024
Edited: Aquatris on 12 Jun 2024
G gain is set for element wise multiplication instead of matrix multiplication, hence (1,4).*(4,1) = (4,4).
x = ones(4,1);
G = ones(1,4);
size(G.*x) % element wise multiplication
ans = 1x2
4 4
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
size(G*x) % matrix multiplication
ans = 1x2
1 1
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
Set the "Multiplication"drop down menu for the G gain to 'matrix multiplication'.

More Answers (0)

Categories

Find more on Simulink in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!