定义一个数组时Mathematica会自动把它当做列矩阵，但在相乘时不存在你说的困难，因为Mathematica会自动根据乘法把你的矩阵看成1×4矩阵或者4×1矩阵。援引Mathematica帮助里的说明：比如如果你输入，m = {{a, b}, {c, d}} ; v = {x, y}然后输入m . v那么结果是{a x + b y, c x + d y}附有说明：This left‐multiplies the vector v by m. The object v is effectively treated as a column vector in this case. ...
