I am having trouble with the if cycle.

kontrl = 3.197442310920451e-14

if kontrl>=-10^-20 & kontrl<=10^-20
  a = 4
  else 
  a = 10
end

% "a = 4" should be.

[Stephen23]

@Muhendisleksi: your upper bound is much smaller than kontrl:

>> 10^-20 <= 3.197442310920451e-14
ans = 1

Why do you think that a should be 4 ?

[Jan]

Note: While 10^-20 is an expensive power operation, 1e-20 is a cheap constant.

Answer 1

[Walter Roberson]

No, that is not correct. "a=4" is given only for values that are in the range +/- 1/10^20 but your value is more than 3000000 times larger than the upper end of that, at roughly +3/10^14

[Muhendisleksi]

"kontrl" is constantly changing. How can I make this dynamic?

[Walter Roberson]

a = zeros(1, 100);
for N = 1 : 100
  kontrl = randn(1,1) * 1E-20;

    if kontrl>=-10^-20 & kontrl<=10^-20
      a(N) = 4;
    else 
      a(N) = 10;
    end
  end

a