public function cond()
    {
        return $this->s[0] / $this->s[min($this->m, $this->n) - 1];
    }
public function cond()
    {
        return $this->s[0] / $this->s[min($this->m, $this->n) - 1];
    }
public function cond ( ) { return $ this -> s [ 0 ] / $ this -> s [ min ( $ this -> m , $ this -> n ) - 1 ] ; }
Two norm condition number

@access public
@return max(S)/min(S)
Two norm condition number