复制
numpy.copyto(dst,src[,casting,where])
累积和
np.cumsum():返回累积和
改变数组形状
- np.shape(a,newshape[,order]):gives a new shape to an array changing its data.
- np.ravel(a,order):Return a contiguous flattened array.
- np.flat():A 1-D iterator over the array
- ndarray.flatten(order=’C’)
Return a copy of the array collapsed into one dimension.
Parameters order [{‘C’, ‘F’, ‘A’, ‘K’}, optional]
‘C’ means to flatten in row-major (C-style) order.
‘F’ means to flatten in column-major (Fortran- style) order.
‘A’ means to flatten in columnmajor order if a is Fortran contiguous in memory, row-major order otherwise.
‘K’ means to flatten a in the order the elements occur in memory.
The default is ‘C’.
Returns :y [ndarray] A copy of the input array, flattened to one dimension.
hsplit()
Split an array into multiple sub-arrays horizontally (column-wise)
x =array([[ 0., 1., 2., 3.],
[ 4., 5., 6., 7.],
[ 8., 9., 10., 11.],
[ 12., 13., 14., 15.]])
np.hsplit(x, np.array([3, 6]))
[array([[ 0., 1., 2.],
[ 4., 5., 6.],
[ 8., 9., 10.],
[ 12., 13., 14.]]),
array([[ 3.],
[ 7.],
[ 11.],
[ 15.]]),
array([], dtype=float64)]
转置操作(Transpose-like operations)
- moveaxis(a, source, destination) Move axes of an array to new positions.
- rollaxis(a, axis[, start]) Roll the specified axis backwards, until it lies in a given position.
- swapaxes(a, axis1, axis2) Interchange two axes of an array.
- ndarray.T Same as self.transpose(), except that self is returned if
self.ndim < 2. - transpose(a[, axes]) Permute the dimensions of an array
Rearranging elements(重排数组元素)
- flip(m[, axis]) Reverse the order of elements in an array along the given
axis. 反转数组 - fliplr(m) Flip array in the left/right direction.
- flipud(m) Flip array in the up/down direction.
- reshape(a, newshape[, order]) Gives a new shape to an array without changing its data.
- roll(a, shift[, axis]) Roll array elements along a given axis.滚动数组,将数组按照循环队列的形式进行平移滚动。
- rot90(m[, k, axes]) Rotate an array by 90 degrees in the plane specified by axes.