several questions for a beginner

hello, I am trying to figure out when I have to use the "." sign before mathematical operations. I read that by writing, for example, v1.*v2, I mean that the multiplying is between the vectors components. On the other hand there were some cases in which it was written v1(3)*v2(3) without the "." So I try to understand when I should use it. thanks

Answer 1

[Stephen23]

The difference is explained here:

https://www.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html

Short summary:

• matrix operations ( without the dot) use rules of linear algebra, or solve systems of equations.
• array operations ( with the dot) perform element-wise operations.

Read the link above and the help for each specific operator to know what it does. More detailed explanations:

https://www.mathworks.com/matlabcentral/answers/417192-what-is-the-different-between-b-2-and-b-2

https://www.mathworks.com/matlabcentral/answers/417469-issue-with-a-a

[Image Analyst]

Eliraz's "Answer" moved here since it's a comment to Stephen rather than an "Answer" by Elirah to his original question.

thanks a lot!