Array manipulation routines¶
Basic operations¶
copyto (dst, src[, casting, where]) |
Copies values from one array to another, broadcasting as necessary. |
Changing array shape¶
reshape (a, newshape[, order]) |
Gives a new shape to an array without changing its data. |
ravel (a[, order]) |
Return a contiguous flattened array. |
ndarray.flat |
A 1-D iterator over the array. |
ndarray.flatten ([order]) |
Return a copy of the array collapsed into one dimension. |
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. |
Changing number of dimensions¶
atleast_1d (*arys) |
Convert inputs to arrays with at least one dimension. |
atleast_2d (*arys) |
View inputs as arrays with at least two dimensions. |
atleast_3d (*arys) |
View inputs as arrays with at least three dimensions. |
broadcast |
Produce an object that mimics broadcasting. |
broadcast_to (array, shape[, subok]) |
Broadcast an array to a new shape. |
broadcast_arrays (*args, **kwargs) |
Broadcast any number of arrays against each other. |
expand_dims (a, axis) |
Expand the shape of an array. |
squeeze (a[, axis]) |
Remove single-dimensional entries from the shape of an array. |
Changing kind of array¶
asarray (a[, dtype, order]) |
Convert the input to an array. |
asanyarray (a[, dtype, order]) |
Convert the input to an ndarray, but pass ndarray subclasses through. |
asmatrix (data[, dtype]) |
Interpret the input as a matrix. |
asfarray (a[, dtype]) |
Return an array converted to a float type. |
asfortranarray (a[, dtype]) |
Return an array laid out in Fortran order in memory. |
ascontiguousarray (a[, dtype]) |
Return a contiguous array in memory (C order). |
asarray_chkfinite (a[, dtype, order]) |
Convert the input to an array, checking for NaNs or Infs. |
asscalar (a) |
Convert an array of size 1 to its scalar equivalent. |
require (a[, dtype, requirements]) |
Return an ndarray of the provided type that satisfies requirements. |
Joining arrays¶
concatenate ((a1, a2, …)[, axis, out]) |
Join a sequence of arrays along an existing axis. |
stack (arrays[, axis, out]) |
Join a sequence of arrays along a new axis. |
column_stack (tup) |
Stack 1-D arrays as columns into a 2-D array. |
dstack (tup) |
Stack arrays in sequence depth wise (along third axis). |
hstack (tup) |
Stack arrays in sequence horizontally (column wise). |
vstack (tup) |
Stack arrays in sequence vertically (row wise). |
block (arrays) |
Assemble an nd-array from nested lists of blocks. |
Splitting arrays¶
split (ary, indices_or_sections[, axis]) |
Split an array into multiple sub-arrays. |
array_split (ary, indices_or_sections[, axis]) |
Split an array into multiple sub-arrays. |
dsplit (ary, indices_or_sections) |
Split array into multiple sub-arrays along the 3rd axis (depth). |
hsplit (ary, indices_or_sections) |
Split an array into multiple sub-arrays horizontally (column-wise). |
vsplit (ary, indices_or_sections) |
Split an array into multiple sub-arrays vertically (row-wise). |
Tiling arrays¶
tile (A, reps) |
Construct an array by repeating A the number of times given by reps. |
repeat (a, repeats[, axis]) |
Repeat elements of an array. |
Adding and removing elements¶
delete (arr, obj[, axis]) |
Return a new array with sub-arrays along an axis deleted. |
insert (arr, obj, values[, axis]) |
Insert values along the given axis before the given indices. |
append (arr, values[, axis]) |
Append values to the end of an array. |
resize (a, new_shape) |
Return a new array with the specified shape. |
trim_zeros (filt[, trim]) |
Trim the leading and/or trailing zeros from a 1-D array or sequence. |
unique (ar[, return_index, return_inverse, …]) |
Find the unique elements of an array. |
Rearranging elements¶
flip (m, axis) |
Reverse the order of elements in an array along the given axis. |
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. |
rot90 (m[, k, axes]) |
Rotate an array by 90 degrees in the plane specified by axes. |