how to find sum different data for two different variables using loop in matlab

I have different datas for two different variables (lambdai and b1). I need to find the separate M1 values and need to find sum M1 also. I couldn't find the answer. let me know if you will get the answer.

clc
clear all 
lambdai=[0 5.6 22.4 57.4];
b1 = [100 80 120 90 70];
k=1
j=1;
l=1;
m=1;
for i=1:length(lambdai)
    for s=1:length(b1)
        M1=(b1(s).*lambdai(i))./lambda;
        M(j,k)=M1;
        j=j+1;
        k=k+1;
    end
end
sumM=sum(M)

[Jan]

The questoin is not clear. What does this mean: "find the separate M1 values and need to find sum M1"?

What is "lambda"?

[Walter Roberson]

sumM = sum(M(:)) 

if you want the sum of the entire matrix.

[M.Rameswari Sudha]

yes. lamda = 100

[Andy]

Once I set a value for lambda it works, All the values for M1 are stored in the array M(. , . ) . sum(M) is calculated as expected but perhaps you want to sum all numbers in the array in which case it should be

sumM = sum(M , 'all');

Answer 1

[Jan]

Maybe you want to do: "Multiply each element of vector a with all elements of vector b, devide by 100 and get the sum of all results."

If you formulate the procedure clearly in naturla language, this is a good structure for the Matlab code also.

lambdai = [0 5.6 22.4 57.4];
b1      = [100 80 120 90 70];
lambda  = 100;
M       = zeros(length(lambdai), length(b1));
for i = 1:length(lambdai)
    for s = 1:length(b1)
        M(i, s) = b1(s) * lambdai(i) / lambda;
    end
end
sumM = sum(M, 'all')

sumM = 392.8400

Of course you do not have to devide each element by lambda, because it is sufficient to divide the result only.

Matlab offers a way to do this without loops:

lambdai = [0 5.6 22.4 57.4];
b1      = [100 80 120 90 70];
lambda  = 100;
M       = lambdai.' * b1;   % dyadic product: [4x1]*[1x5] = [4x5]
% Or:
% M     = lambdai .* b1.';  % elementwise product: [1x4]*[5x1] = [5x4]

sumM    = sum(M, 'all') / lambda

sumM = 392.8400

[M.Rameswari Sudha]

I got answer. Thank you for your immediate response.

Answer 2

[M.Rameswari Sudha]

I got error using code as per you sent :

??? Error using ==> sum

Trailing string input must be 'double' or 'native'.

let me know the reason why I got error.

[Jan]

sum(X, 'all') was introduced in modern Matlab versions. For old versions use: sum(X(:)) instead.