This is documentation for an old release of NumPy (version 1.8.0). Read this page Search for this page in the documentation of the latest stable release (version > 1.17).
Array manipulation routines
Basic operations
copyto(dst, src[, casting, where, preservena]) |
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 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
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_arrays(*args) |
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. |
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
column_stack(tup) |
Stack 1-D arrays as columns into a 2-D array. |
concatenate((a1, a2, ...)[, axis]) |
Join a sequence of arrays together. |
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). |
Splitting 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). |
split(ary, indices_or_sections[, axis]) |
Split an array into multiple sub-arrays. |
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
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]) |
Rotate an array by 90 degrees in the counter-clockwise direction. |