为什么此高斯函数会给出不一致的参数错误？

Question

function m=gaussian(med, var, n)
  if ( mod(n, 2)==0 )
      n=n+1;
  end;

  med=double(med);
  var=double(var);

  med = min (max(-(n+1)/2, med),  (n+1)/2);

  m=zeros(1,n);

  k1=(1/(2*pi*var)^0.5);
  k2=-0.5.*((med-(1:n)).^2)./var;

  m(1,1:n)=k1.*exp(k2);

Output1

>> gaussian([101 2 ; 3 4], [4 301 ; 2 1], [2 2])
error: gaussian: operator /: nonconformant arguments (op1 is 1x1, op2 is 2x2)
error: called from
    gaussian at line 13 column 5
>>

Output2

>> gaussian([101 2 ; 3 4], [4 301 ; 2 1], 2)
error: gaussian: operator /: nonconformant arguments (op1 is 1x1, op2 is 2x2)
error: called from
    gaussian at line 13 column 5

Answer 1

I'm unsure what you wanted the result to be but you get that error because you're doing matrix division of a scalar ( [1x1] dimensions) by a [2x2] matrix. Note, you're doing matrix division ( / operator) and not a element by element division ( ./ operator).

octave:1> function m=gaussian(med, var, n)
>   if ( mod(n, 2)==0 )
>       n=n+1;
>   end;
> 
>   med=double(med);
>   var=double(var);
> 
>   med = min (max(-(n+1)/2, med),  (n+1)/2);
> 
>   m=zeros(1,n);
> 
>   k1=(1/(2*pi*var)^0.5);
>   k2=-0.5.*((med-(1:n)).^2)./var;
> 
>   m(1,1:n)=k1.*exp(k2);
> endfunction
octave:2> debug_on_error (1)
octave:3> gaussian ([101 2 ; 3 4], [4 301 ; 2 1], 2)
error: gaussian: operator /: nonconformant arguments (op1 is 1x1, op2 is 2x2)
error: called from
    gaussian at line 13 column 5
stopped in gaussian at line 13
13:   k1=(1/(2*pi*var)^0.5);
debug> (2*pi*var)
ans =

     25.1327   1891.2388
     12.5664      6.2832

debug> 1/(2*pi*var) # matrix division
error: gaussian: operator /: nonconformant arguments (op1 is 1x1, op2 is 2x2)
error: called from
    gaussian at line 13 column 5
debug> 1./(2*pi*var) # your element by element division works
ans =

   0.03978874   0.00052875
   0.07957747   0.15915494

However, that's not the only issue since the following line has a similar issue for the minus operator:

error: gaussian: operator -: nonconformant arguments (op1 is 2x2, op2 is 1x3)
error: called from
    gaussian at line 14 column 5
stopped in gaussian at line 14
14:   k2=-0.5.*((med-(1:n)).^2)./var;

Alternatively, maybe the functions is not incorrect, and you're getting those errors because you're calling the function incorrectly.