Allow normrnd to return empty matrix.

[AvanishSalunke]

closes #364

[pr0m1th3as]

Your fix is is not covering for

>> normrnd (0,1,[1,0,1])
ans = [](1x0)
>> normrnd (0,1,[5,0,1])
ans = [](5x0)
>> normrnd (0,1,[5,0,2, 1])
ans = [](5x0x2)

The if (isempty) statement is a good start, but assigning [] for every case will not cut it

[pr0m1th3as]

BTW, is this behavior only limited to normrnd in MATLAB? I doubt this, but you should check first. If this affects all *rnd distribution functions, then whatever fix we come up for normrnd should be applied to all other rnd functions.

[AvanishSalunke]

BTW, is this behavior only limited to normrnd in MATLAB? I doubt this, but you should check first. If this affects all *rnd distribution functions, then whatever fix we come up for normrnd should be applied to all other rnd functions.

that was exactly what i was thinking of, this minute check might be missing with other rnd functions as well, if yes we can fix it.
Thanks !!

[AvanishSalunke]

@pr0m1th3as
Matlab also returns the same :

>> normrnd (0,1,[1,0,1])

ans =

  1×0 empty double row vector

>> normrnd (0,1,[5,0,1])

ans =

  5×0 empty double matrix

>> normrnd (0,1,[5,0,2, 1])

ans =

  5×0×2 empty double array

also the else conditions cover it perfectly :

    if (isempty (varargin{1}))
        sz = [0, 0];
    elseif (isscalar (varargin{1}) && varargin{1} >= 0 ...
                               && varargin{1} == fix (varargin{1}))
      sz = [varargin{1}, varargin{1}];
    elseif (isrow (varargin{1}) && all (varargin{1} >= 0) ...
                                && all (varargin{1} == fix (varargin{1})))
      sz = varargin{1};
    else
      error (strcat ("normrnd: SZ must be a scalar or a row vector", ...
                     " of non-negative integers."));
    endif

I also checked another function ncx2rnd it also does the same, so fixes for *rnd functios would be needed