How to write the code in Matlab for the the double summation attached below.

Answer 1

[Torsten]

n = 5;
m = 10;
p = rand(n,m);
C = rand(1,m);
dt = 0.2;
F1 = dt*sum(sum(C.*p))

F1 = 3.3520

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Answer 2

[RANGA BHARATH]

Hi @Bijaya Das. Here is the solution and code for your question.

Question: How to write the code to perform double summation (for the equation attached)?

Solution:

According to the provided equation, it can be clearly seen that 'C' is a one-dimensional vector (column or row vector) of length m and 'p' is a 2D array with shape (n,m) or (m,n). One of the approaches is to use normal matrix multiplication for the inner sum and then use 'sum' function for outer sum.

Assumptions:

• Let us assume C as a column vector of shape (m,1) and p as a 2D matrix of shape (n,m).
• Here, I'm using integers to perform this task as it would be easy to understand.
• And the values taken are: m = 3, n = 2, range of integers used = 1 to 5, deltat = 0.5.

Code:

n = 3;
m = 2;
p = randi([1,5],n,m)
C = randi([1,5],m,1)
deltat = 0.5;

temp = p*C*deltat
f1 = sum(temp,1)

Links to Documentation:

• Here is the link to the documentation of 'randi' function which generates random integers of between specified range and of specified shape https://www.mathworks.com/help/matlab/ref/randi.html..
• Here is the link to the documentation of 'sum' function Sum of array elements - MATLAB sum (mathworks.com).

[Bijaya Das]

Thank you...