What does mean .* and ' ?

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Oliver Lestrange
Oliver Lestrange on 16 Aug 2020
Answered: Steven Lord on 7 Sep 2020
Hi,
It seems that in MATLAB exists the notation .* that seems to be an operation and the notation ' that is used apparently with variables.
What is the meaning of these notations?

Accepted Answer

KSSV
KSSV on 16 Aug 2020
Edited: KSSV on 16 Aug 2020
.* this mean element by element multiplication. https://www.mathworks.com/help/matlab/ref/times.html
Example:
A = [1 2 ; 3 4] ;
B = [5 6 ; 7 8] ;
C = A.*B
' this stands for transpose of a matrix. https://www.mathworks.com/help/matlab/ref/transpose.html
EXample:
A = [1 2 ; 3 4] ;
B = A'
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More Answers (2)

Sara Boznik
Sara Boznik on 16 Aug 2020
.* means matrix product, if you don't write . will Matlab product the numbers on the same position.
' you use it usually when you want to have something displayed in Command Window.
Good luck.
  1 Comment
Stephen
Stephen on 7 Sep 2020
".* means matrix product, if you don't write . will Matlab product the numbers on the same position."
This is incorrect. In fact:
The difference is explained here:
"' you use it usually when you want to have something displayed in Command Window."
The complex conjugate transpose should be used when you need the complex conjugate transpose.

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Steven Lord
Steven Lord on 7 Sep 2020
The .* operator performs element-wise multiplication.
The ' character has at least three potential meanings that I can think of offhand.
The first potential meaning is that of the complex conjugate transpose.
A = [1 2+3i; 4 5+5i]
B = A'
Note that each row in B contains the same values as the corresponding column of A, except that complex numbers are replaced with their complex conjugates.
The second potential meaning is to create a char vector. This could be what Sara Boznik meant with "you use it usually when you want to have something displayed in Command Window."
x = 'apple'
The third is relevant inside a char vector. Two ' characters will create a single ' stored inside the char vector.
y = 'Simple, isn''t it?'

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