MATLAB: Multiplying vector members without repeating

combinationsmultiplyvector

Hi I need to multiply values from one vector in all combinations. For example Lets say that vector A=[1 2 3 4]' I need to get these products 1*2 1*3 1*4 2*3 2*4 3*4

Thanks for help

Best Answer

>> A = 1:4;
>> prod(nchoosek(A,2),2)
ans =
    2
    3
    4
    6
    8
   12

Related Solutions

MATLAB: Repeating elements (vector)

There are most likely much more efficient algorithms than this:

>> N = 4;
>> X = (1:N)'*ones(1,N);
>> X(triu(true(N)))
ans =
   1
   1
   2
   1
   2
   3
   1
   2
   3
   4

You can use X as indices into your vector to select the values that you want.

MATLAB: Symbolic Matrix members evaluation

Why do you want to create variable names like A1_3, A2_3, etc., when you can directly index the matrix A. Creating a separate variable name for each element is not an efficient coding approach: https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval.

Also, MATLAB does not provide a good way of doing what you want to do.

Best Answer

Related Solutions

MATLAB: Repeating elements (vector)

MATLAB: Symbolic Matrix members evaluation

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