numpy或pandas中reshape(-1)等用法
- 2020 年 4 月 8 日
- 筆記
例：
z = np.array([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], [13, 14, 15, 16]]) z.shape (4, 4)
1.z.reshape(-1)或z.reshape(1,-1)将数组横向平铺
z.reshape(-1) array([ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16])
2.z.reshape(-1, 1)将数组纵向平铺
z.reshape(-1,1) array([[ 1], [ 2], [ 3], [ 4], [ 5], [ 6], [ 7], [ 8], [ 9], [10], [11], [12], [13], [14], [15], [16]])
3.z.reshape(-1, 2)
newshape等于-1，列数等于2，行数未知，reshape后的shape等于(8, 2)
z.reshape(-1, 2) array([[ 1, 2], [ 3, 4], [ 5, 6], [ 7, 8], [ 9, 10], [11, 12], [13, 14], [15, 16]])
