size function says not enough input arguments

function y = mypnz(x)
% negative positive zero
 
 
[m,n] = size(x);
 
pp = 0;
nn = 0;
zz = 0;
 
for a = 1:m 
for b = 1:n
if x (a,b) < 0 
nn= nn+1 ;
end %if
if x (a,b) > 0 
pp= pp+1 ;
      end %if
      if x (a,b) == 0
         zz = zz+1 ;
      end %if
   end % for-xb
end % for-a
 
y= [pp nn zz];

i'm very new to matlab but how do i get the size (x) line to work? i t works when i run it in the command window

Answer 1

[Walter Roberson]

You cannot run that code by pressing the green Run button. When you press the green Run button then the function is executed with no arguments. You need to go down to the command line and run the function with an argument.