MATLAB: How to write a summation code when the k is not equal to j

double sumsumsummation

I want to write the code like this,and the rage of k is 1 to K,but i don't know how to write the " j is not equal to k" this summation code,can anyone show me how to write it ?

Best Answer

yang-En, haven't heard from you. If the vectorized approach above is to confusing to you then try this simple and intuitive for loop. It basically uses the "continue" command to skip interations where j = k.
numPoints = 3; % Whatever...

lambda = randi(9, 1, numPoints) % Whatever...
f = randi(9, 1, numPoints) % Whatever...
h = randi(9, 1, numPoints) % Whatever...
K = length(lambda)
outerSum = 0;
for k = 1 : K
innerSum = 0;
% Do the inner sum over j with j not equal to k
for j = 1 : length(h)
if j == k
continue; % Skip this iteration
innerSum = innerSum + h(j) * f(k);
outerSum = outerSum + lambda(k) * innerSum;
outerSum % Spew out to the command window so we can see what it is.