function [v, idx] = owuitools_topk (x, k, direction, fname, varargin)
  %OWUITOOLS_TOPK  Shared body of the maxk/mink shims.

  if (~isempty (varargin))
    error ('%s: this shim takes only (x, k) - no dimension or option arguments', fname);
  end
  if (~isnumeric (x) && ~islogical (x))
    error ('%s: x must be numeric', fname);
  end
  if (~isnumeric (k) || ~isscalar (k) || k < 0 || k ~= fix (k))
    error ('%s: k must be a non-negative integer', fname);
  end

  if (isvector (x) || isempty (x))
    [sorted, order] = sort (x(:), direction);
    n = min (k, numel (sorted));
    v = sorted(1:n);
    idx = order(1:n);
    if (size (x, 1) == 1 && ~isempty (x))     % a row in, a row out
      v = v.';
      idx = idx.';
    end
    return;
  end

  [sorted, order] = sort (x, 1, direction);
  n = min (k, size (sorted, 1));
  v = sorted(1:n, :);
  idx = order(1:n, :);
end