Array creation routines¶
See also
Ones and zeros¶
empty (shape[, dtype, order]) |
Return a new array of given shape and type, without initializing entries. |
empty_like (a[, dtype, order, subok]) |
Return a new array with the same shape and type as a given array. |
eye (N[, M, k, dtype, order]) |
Return a 2-D array with ones on the diagonal and zeros elsewhere. |
identity (n[, dtype]) |
Return the identity array. |
ones (shape[, dtype, order]) |
Return a new array of given shape and type, filled with ones. |
ones_like (a[, dtype, order, subok]) |
Return an array of ones with the same shape and type as a given array. |
zeros (shape[, dtype, order]) |
Return a new array of given shape and type, filled with zeros. |
zeros_like (a[, dtype, order, subok]) |
Return an array of zeros with the same shape and type as a given array. |
full (shape, fill_value[, dtype, order]) |
Return a new array of given shape and type, filled with fill_value. |
full_like (a, fill_value[, dtype, order, subok]) |
Return a full array with the same shape and type as a given array. |
From existing data¶
array (object[, dtype, copy, order, subok, ndmin]) |
Create an 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. |
ascontiguousarray (a[, dtype]) |
Return a contiguous array in memory (C order). |
asmatrix (data[, dtype]) |
Interpret the input as a matrix. |
copy (a[, order]) |
Return an array copy of the given object. |
frombuffer (buffer[, dtype, count, offset]) |
Interpret a buffer as a 1-dimensional array. |
fromfile (file[, dtype, count, sep]) |
Construct an array from data in a text or binary file. |
fromfunction (function, shape, **kwargs) |
Construct an array by executing a function over each coordinate. |
fromiter (iterable, dtype[, count]) |
Create a new 1-dimensional array from an iterable object. |
fromstring (string[, dtype, count, sep]) |
A new 1-D array initialized from text data in a string. |
loadtxt (fname[, dtype, comments, delimiter, …]) |
Load data from a text file. |
Creating record arrays (numpy.rec
)¶
Note
numpy.rec
is the preferred alias for
numpy.core.records
.
core.records.array (obj[, dtype, shape, …]) |
Construct a record array from a wide-variety of objects. |
core.records.fromarrays (arrayList[, dtype, …]) |
create a record array from a (flat) list of arrays |
core.records.fromrecords (recList[, dtype, …]) |
create a recarray from a list of records in text form |
core.records.fromstring (datastring[, dtype, …]) |
create a (read-only) record array from binary data contained in a string |
core.records.fromfile (fd[, dtype, shape, …]) |
Create an array from binary file data |
Creating character arrays (numpy.char
)¶
Note
numpy.char
is the preferred alias for
numpy.core.defchararray
.
core.defchararray.array (obj[, itemsize, …]) |
Create a chararray . |
core.defchararray.asarray (obj[, itemsize, …]) |
Convert the input to a chararray , copying the data only if necessary. |
Numerical ranges¶
arange ([start,] stop[, step,][, dtype]) |
Return evenly spaced values within a given interval. |
linspace (start, stop[, num, endpoint, …]) |
Return evenly spaced numbers over a specified interval. |
logspace (start, stop[, num, endpoint, base, …]) |
Return numbers spaced evenly on a log scale. |
geomspace (start, stop[, num, endpoint, dtype]) |
Return numbers spaced evenly on a log scale (a geometric progression). |
meshgrid (*xi, **kwargs) |
Return coordinate matrices from coordinate vectors. |
mgrid |
nd_grid instance which returns a dense multi-dimensional “meshgrid”. |
ogrid |
nd_grid instance which returns an open multi-dimensional “meshgrid”. |
Building matrices¶
diag (v[, k]) |
Extract a diagonal or construct a diagonal array. |
diagflat (v[, k]) |
Create a two-dimensional array with the flattened input as a diagonal. |
tri (N[, M, k, dtype]) |
An array with ones at and below the given diagonal and zeros elsewhere. |
tril (m[, k]) |
Lower triangle of an array. |
triu (m[, k]) |
Upper triangle of an array. |
vander (x[, N, increasing]) |
Generate a Vandermonde matrix. |