operation after every iteration in Nested for loop

for i=1:100 
    for j=1:20:720
        temp1=d2( :, j : j+19 )
        temp2=prod(temp1)     
    end         
end

In the above code, i want that after every 20 th column , a prod operation done then i update a value , then it again takes another 20 coumn like that..but it it printing starting from first 20 col to 720 th col and in every iteration it prints the product..i want to perform some operations like prod and then updation after every 20 th iteration...should i use break command as this code is printing whole result

[VASUNDHARA V]

d2 =(3,720) matrix

Answer 1

[Walter Roberson]

for i=1:100
    for j = 1 : 60
        temp1 = d2( :, j * 60 - 59 : j*60 );
        temp2(j) = prod(temp1);
    end
end

Question: Why are you doing the exact same thing 100 times?

[VASUNDHARA V]

indices not matched while writing temp2(j)

[Walter Roberson]

for i=1:100
  for j = 1 : 60
      temp1 = d2( :, j * 60 - 59 : j*60 );
      temp2(:, j) = prod(temp1, 2);
  end

This assumes that you want the product of each partial row each time. end

[VASUNDHARA V]

Thankyou sir