How to repeat the same function for different matrix ?

Hello,

I have many vectors with different row sizes and I would like to repeat the same function for them.

Example:

A1 = [8; 9; 10]
   
A2 = [1; 2]
  
       
   B1 = [0.1; 0.3; 0.6]
   B2 = [0.5; 0.9]

   
P1 = A1 .* B1
P2 = A2 .* B2
...

How could I do to solve that?

Thanks in advance,

[madhan ravi]

samw function? which function ?

[Rachel Sabioni]

Sorry, I was not clear.

Actually I want to calculate

the vector P

P = A * B

But I want to do that for many vectors A (A1, A2, A3, ...) and vectors B(B1, B2, B3, ...)

I think that I need to created a function, but I do not know how.

[madhan ravi]

Read about function:

doc function % to know more about creating a function

[Luna]

Do you want to get each P for each A and B seperately? or the P will be a long vector?

Also your vectors in your workspace or defined in a variable? Simply you can do this:

vectorA = [A1;A2; .. bla bla .. An];
vectorB = [B1;B2; .. bla bla .. Bn];
vectorP = vectorA .* vectorB;

[Stephen23]

"But I want to do that for many vectors A (A1, A2, A3, ...) and vectors B(B1, B2, B3, ...)"

Numbered variables are a sign that you are doing something wrong.

Dynamically accessing badly named variables is one way that beginners force themselves into writing slow, complex, obfuscated, buggy code that is hard to debug. Read this to know why:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

"How to repeat the same function for different matrix ?"

This is trivial using idnexing.

Indexing is simple, neat, compact, easy to debug, and very efficient (unlike what you are trying to do). You should use indexing, just like experienced MATLAB users do.

Answer 1

[YUNUS AKSOY]

for c=1:2;
eval(['P',num2str(c),'=A',num2str(c),'.*B',num2str(c),';']);
end

[madhan ravi]

Yet another eval() user.

Why using eval() is evil?

[Stephen23]

Note that the MATLAB documentation specifically recommends avoiding doing this:

https://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html

Dynamically accessing badly named variables is one way that beginners force themselves into writing slow, complex, obfuscated, buggy code that is hard to debug. Read this to know why:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Indexing is simple, neat, compact, easy to debug, and very efficient (unlike what you recommend). Experienced MATLAB users recommend indexing, you can too.

[Rachel Sabioni]

Thank you all for your help and explanations. I am a beginner in MATLAB and yours comments have helped me a lot !!