How to store values from toc into an array

help with bonus question

[Raiven Balderas]

i need help with question 5 and the bonus depicted in the screenshot/attachment

Answer 1

[Walter Roberson]

tic;
for K = 1 : 10
  times(K) = toc;
end

[Raiven Balderas]

%HW3.m

im trying to do question 5 of my homework but it isn't working. the homework question is provided in link/attachment

      counter=0;
  for n=[1E1 1E2 1E3 1E4 1E5]
      timeslow=zeros(1,5)
      tic;p=prime_list_slow_class(n);timeslow=toc
      counter=counter+1;
  end

      counter=1;
  for n=[1E1 1E2 1E3 1E4 1E5]
      timeslist=zeros(1,5);
      tic;p=prime_list(n);timeslist =toc
      counter=counter+1;
  end

      counter=2;
  for n=[1E1 1E2 1E3 1E4 1E5]
      timesieve=zeros(1,5);
      tic;p=prime_sieve(n);timesieve=toc
      counter=counter+1;
  end

figure(3);
hold on;

      loglog(timeslow,[1E1 1E2 1E3 1E4 1E5],'b-','linewidth',3); hold on
      loglog(timeslist,[1E1 1E2 1E3 1E4 1E5],'r-','linewidth',3); hold on
      loglog(timesieve,[1E1 1E2 1E3 1E4 1E5],'g-','linewidth',3); hold on

[Walter Roberson]

You are overwriting all of timeslow, timeslist, timesieve each iteration of the loop.

for N = 1 : 5
 n = 10^N;
 ...
 timeslow(n) = toc;
 ...
end

[Raiven Balderas]

still not plotting,nor working. thanks though.

[Walter Roberson]

Only initialize timeslow to zero before the for loop, not in the for loop.

[Raiven Balderas]

thanks, how do i do the bonus ?

[Walter Roberson]

You write a function named prime_count that takes n as an input and returns a vector named Upsilon which is of length n, each element of which is the number of prime numbers less than or equal to its index. The function prime_count must call prime_sieve exactly once -- however, it is not required that your function use the results returned by prime_sieve .