I get Subscript indices must either be real positive integers or logicals.

if true
  % N = 5000;
    z = 2*randn(N,1);
    x = (-9:0.25:9);

      z1 = reshape(z,[10,500]);
      y = mean(z1);
      sdy = std(y);

      E = exp(-(x.^2)./(2*(sdy^2)));
      DeltaNy = (500./(sdy*sqrt(2*pi))).*E.*0.25;
      plot(x,DeltaNy,'r-');
  end

I have to use the formula for delta n which depends on the standard deviation of y but this values is too small and 
I get Subscript indices must either be real positive integers or logicals. I don't know how to make the formula work, I need it to plot the normal distribution on a histogram. I have to use THAT formula and cant change it.

Answer 1

[Star Strider]

The code you posted runs without error for me (in R2017b).

If it is throwing an error, please copy the complete error message (all the red text) from your Command Window and paste it to a Comment here.

[Gonzalo Reina]

The error is Subscript indices must either be real positive integers or logicals.

Error in SET4 (line 31) E = exp(-(x.^2)./(2*(sdy^2)));

[Star Strider]

The only possibility I see is that you have a variable called exp already defined in your code.

If this:

which exp -all

returns ‘exp is a variable’, you have found the problem. (The solution is to find that variable assignment and then to rename the variable to something else.)

[Gonzalo Reina]

yep found it, thanks a lot I hate it when I get errors that are easy to fix but I just can't get. I just started with matlab after all

[Star Strider]

My pleasure.

If my Answer helped you solve your problem, please Accept it!

[Image Analyst]

When k is 1, then k-5 is -4. You can't have a negative 4 as the row number of a matrix.

Answer 2

[Image Analyst]

It's well explained by the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_fix_the_error_.22Subscript_indices_must_either_be_real_positive_integers_or_logicals..22.3F