nums.numpy.api.creation module
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nums.numpy.api.creation.
arange
(start=None, stop=None, step=1, dtype=None)[source] Return evenly spaced values within a given interval.
This docstring was copied from numpy.arange.
Some inconsistencies with the NumS version may exist.
Values are generated within the half-open interval
[start, stop)
(in other words, the interval including start but excluding stop). For integer arguments the function is equivalent to the Python built-in range function, but returns an BlockArray rather than a list.When using a non-integer step, such as 0.1, the results will often not be consistent. It is better to use nums.linspace for these cases.
- Parameters
start (number, optional) – Start of interval. The interval includes this value. The default start value is 0.
stop (number) – End of interval. The interval does not include this value, except in some cases where step is not an integer and floating point round-off affects the length of out.
step (number, optional) – Spacing between values. For any output out, this is the distance between two adjacent values,
out[i+1] - out[i]
. The default step size is 1. If step is specified as a position argument, start must also be given.dtype (dtype) – The type of the output array. If dtype is not given, infer the data type from the other input arguments.
- Returns
arange – Array of evenly spaced values.
For floating point arguments, the length of the result is
ceil((stop - start)/step)
. Because of floating point overflow, this rule may result in the last element of out being greater than stop.- Return type
See also
linspace
Evenly spaced numbers with careful handling of endpoints.
Notes
Only step size of 1 is currently supported.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.arange(3).get() array([0, 1, 2]) >>> nps.arange(3.0).get() array([ 0., 1., 2.]) >>> nps.arange(3,7).get() array([3, 4, 5, 6])
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nums.numpy.api.creation.
array
(object, dtype=None, copy=True, order='K', ndmin=0, subok=False)[source] Creates a BlockArray.
This docstring was copied from numpy.array.
Some inconsistencies with the NumS version may exist.
- Parameters
object (array_like) – An array, any object exposing the array interface, an object whose __array__ method returns an array, or any (nested) sequence.
dtype (data-type, optional) – The desired data-type for the array. If not given, then the type will be determined as the minimum type required to hold the objects in the sequence.
copy (bool, optional) – If true (default), then the object is copied. Otherwise, a copy will only be made if __array__ returns a copy, if obj is a nested sequence, or if a copy is needed to satisfy any of the other requirements (dtype, order, etc.).
order ({'K'}, optional) –
Specify the memory layout of the array. If object is not an array, the newly created array will be in C order (row major) unless ‘F’ is specified, in which case it will be in Fortran order (column major). If object is an array the following holds.
order
no copy
copy=True
’K’
unchanged
F & C order preserved, otherwise most similar order
’A’
unchanged
F order if input is F and not C, otherwise C order
’C’
C order
C order
’F’
F order
F order
When
copy=False
and a copy is made for other reasons, the result is the same as ifcopy=True
, with some exceptions for A, see the Notes section. The default order is ‘K’.subok (bool, optional) – If True, then sub-classes will be passed-through, otherwise the returned array will be forced to be a base-class array (default).
ndmin (int, optional) – Specifies the minimum number of dimensions that the resulting array should have. Ones will be pre-pended to the shape as needed to meet this requirement.
- Returns
out – An array object satisfying the specified requirements.
- Return type
See also
empty_like
Return an empty array with shape and type of input.
ones_like
Return an array of ones with shape and type of input.
zeros_like
Return an array of zeros with shape and type of input.
full_like
Return a new array with shape of input filled with value.
empty
Return a new uninitialized array.
ones
Return a new array setting values to one.
zeros
Return a new array setting values to zero.
full
Return a new array of given shape filled with value.
Notes
Only order=’K’ is supported.
Only ndmin=0 is currently supported.
subok must be False
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.array([1, 2, 3]).get() array([1, 2, 3])
Upcasting:
>>> nps.array([1, 2, 3.0]).get() array([ 1., 2., 3.])
More than one dimension:
>>> nps.array([[1, 2], [3, 4]]).get() array([[1, 2], [3, 4]])
Type provided:
>>> nps.array([1, 2, 3], dtype=complex).get() array([ 1.+0.j, 2.+0.j, 3.+0.j])
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nums.numpy.api.creation.
copy
(a, order='K', subok=False)[source] Return an array copy of the given object.
This docstring was copied from numpy.copy.
Some inconsistencies with the NumS version may exist.
- Parameters
a (BlockArray) – Input data.
order ({'C', 'F', 'A', 'K'}, optional) – Controls the memory layout of the copy. ‘C’ means C-order, ‘F’ means F-order, ‘A’ means ‘F’ if a is Fortran contiguous, ‘C’ otherwise. ‘K’ means match the layout of a as closely as possible. (Note that this function and
BlockArray.copy()
are very similar, but have different default values for their order= arguments.)subok (bool, optional) – If True, then sub-classes will be passed-through, otherwise the returned array will be forced to be a base-class array (defaults to False).
- Returns
arr – Array interpretation of a.
- Return type
See also
copy
Preferred method for creating an array copy
Notes
This is equivalent to:
>>> nps.array(a, copy=True).get()
Only default args supported.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.Create an array x, with a reference y and a copy z:
>>> x = nps.array([1, 2, 3]) >>> y = x >>> z = nps.copy(x)
Note that, when we modify x, y changes, but not z:
>>> x[0] = 10 >>> (x[0] == y[0]).get() array(True) >>> (x[0] == z[0]).get() False
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nums.numpy.api.creation.
diag
(v, k=0)[source] Extract a diagonal or construct a diagonal array.
This docstring was copied from numpy.diag.
Some inconsistencies with the NumS version may exist.
See the more detailed documentation for
numpy.diagonal
if you use this function to extract a diagonal and wish to write to the resulting array; whether it returns a copy or a view depends on what version of numpy you are using.- Parameters
v (BlockArray) – If v is a 2-D array, return a copy of its k-th diagonal. If v is a 1-D array, return a 2-D array with v on the k-th diagonal.
k (int, optional) – Diagonal in question. The default is 0. Use k>0 for diagonals above the main diagonal, and k<0 for diagonals below the main diagonal.
- Returns
out – The extracted diagonal or constructed diagonal array.
- Return type
See also
diagonal
Return specified diagonals.
trace
Sum along diagonals.
triu
Upper triangle of an array.
Notes
offset != 0 is currently not supported.
out is currently not supported.
axis1 != 0 or axis2 != 1 is currently not supported.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> x = nps.arange(9).reshape((3,3)) >>> x.get() array([[0, 1, 2], [3, 4, 5], [6, 7, 8]])
>>> nps.diag(x).get() array([0, 4, 8])
>>> nps.diag(nps.diag(x)).get() array([[0, 0, 0], [0, 4, 0], [0, 0, 8]])
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nums.numpy.api.creation.
empty
(shape, dtype=<class 'float'>)[source] Return a new array of given shape and type, without initializing entries.
This docstring was copied from numpy.empty.
Some inconsistencies with the NumS version may exist.
- Parameters
shape (int or tuple of int) – Shape of the empty array, e.g.,
(2, 3)
or2
.dtype (data-type, optional) – Desired output data-type for the array, e.g, int. Default is float.
- Returns
out – Array of uninitialized (arbitrary) data of the given shape and dtype.
- Return type
See also
empty_like
Return an empty array with shape and type of input.
ones
Return a new array setting values to one.
zeros
Return a new array setting values to zero.
full
Return a new array of given shape filled with value.
Notes
empty, unlike zeros, does not set the array values to zero, and may therefore be marginally faster. On the other hand, it requires the user to manually set all the values in the array, and should be used with caution.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.empty([2, 2]).get() array([[ -9.74499359e+001, 6.69583040e-309], [ 2.13182611e-314, 3.06959433e-309]]) #uninitialized
>>> nps.empty([2, 2], dtype=int).get() array([[-1073741821, -1067949133], [ 496041986, 19249760]]) #uninitialized
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nums.numpy.api.creation.
empty_like
(prototype, dtype=None, order='K', shape=None)[source] Return a new array with the same shape and type as a given array.
This docstring was copied from numpy.empty_like.
Some inconsistencies with the NumS version may exist.
- Parameters
prototype (BlockArray) – The shape and data-type of prototype define these same attributes of the returned array.
dtype (data-type, optional) – Overrides the data type of the result.
order ({'C', 'F', 'A', or 'K'}, optional) – Overrides the memory layout of the result. ‘C’ means C-order, ‘F’ means F-order, ‘A’ means ‘F’ if
prototype
is Fortran contiguous, ‘C’ otherwise. ‘K’ means match the layout ofprototype
as closely as possible.shape (int or sequence of ints, optional.) – Overrides the shape of the result. If order=’K’ and the number of dimensions is unchanged, will try to keep order, otherwise, order=’C’ is implied.
- Returns
out – Array of uninitialized (arbitrary) data with the same shape and type as prototype.
- Return type
See also
ones_like
Return an array of ones with shape and type of input.
zeros_like
Return an array of zeros with shape and type of input.
full_like
Return a new array with shape of input filled with value.
empty
Return a new uninitialized array.
Notes
This function does not initialize the returned array; to do that use zeros_like or ones_like instead. It may be marginally faster than the functions that do set the array values.
Only order=’K’ is supported.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> a = ([1,2,3], [4,5,6]) # a is array-like >>> nps.empty_like(a, shape=(2, 3), dtype=float).get() array([[-1073741821, -1073741821, 3], # uninitialized [ 0, 0, -1073741821]]) >>> a = nps.array([[1., 2., 3.],[4.,5.,6.]]).get() >>> nps.empty_like(a, shape=(2, 3), dtype=float).get() array([[ -2.00000715e+000, 1.48219694e-323, -2.00000572e+000], # uninitialized [ 4.38791518e-305, -2.00000715e+000, 4.17269252e-309]])
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nums.numpy.api.creation.
eye
(N, M=None, k=0, dtype=<class 'float'>)[source] Return a 2-D array with ones on the diagonal and zeros elsewhere.
This docstring was copied from numpy.eye.
Some inconsistencies with the NumS version may exist.
- Parameters
N (int) – Number of rows in the output.
M (int, optional) – Number of columns in the output. If None, defaults to N.
k (int, optional) – Index of the diagonal: 0 (the default) refers to the main diagonal, a positive value refers to an upper diagonal, and a negative value to a lower diagonal.
dtype (data-type, optional) – Data-type of the returned array.
- Returns
I – An array where all elements are equal to zero, except for the k-th diagonal, whose values are equal to one.
- Return type
BlockArray of shape (N,M)
See also
Notes
Only k==0 is currently supported.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.eye(2, dtype=int).get() array([[1, 0], [0, 1]]) >>> nps.eye(3, k=1).get() array([[0., 1., 0.], [0., 0., 1.], [0., 0., 0.]])
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nums.numpy.api.creation.
identity
(n, dtype=<class 'float'>)[source] Return the identity array.
This docstring was copied from numpy.identity.
Some inconsistencies with the NumS version may exist.
The identity array is a square array with ones on the main diagonal.
- Parameters
n (int) – Number of rows (and columns) in n x n output.
dtype (data-type, optional) – Data-type of the output. Defaults to
float
.
- Returns
out – n x n array with its main diagonal set to one, and all other elements 0.
- Return type
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.identity(3).get() array([[1., 0., 0.], [0., 1., 0.], [0., 0., 1.]])
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nums.numpy.api.creation.
linspace
(start, stop, num=50, endpoint=True, retstep=False, dtype=None, axis=0)[source] Return evenly spaced numbers over a specified interval.
This docstring was copied from numpy.linspace.
Some inconsistencies with the NumS version may exist.
Returns num evenly spaced samples, calculated over the interval [start, stop].
The endpoint of the interval can optionally be excluded.
- Parameters
start (BlockArray) – The starting value of the sequence.
stop (BlockArray) – The end value of the sequence, unless endpoint is set to False. In that case, the sequence consists of all but the last of
num + 1
evenly spaced samples, so that stop is excluded. Note that the step size changes when endpoint is False.num (int, optional) – Number of samples to generate. Default is 50. Must be non-negative.
endpoint (bool, optional) – If True, stop is the last sample. Otherwise, it is not included. Default is True.
retstep (bool, optional) – If True, return (samples, step), where step is the spacing between samples.
dtype (dtype, optional) – The type of the output array. If dtype is not given, infer the data type from the other input arguments.
axis (int, optional) – The axis in the result to store the samples. Relevant only if start or stop are array-like. By default (0), the samples will be along a new axis inserted at the beginning. Use -1 to get an axis at the end.
- Returns
samples (BlockArray) – There are num equally spaced samples in the closed interval
[start, stop]
or the half-open interval[start, stop)
(depending on whether endpoint is True or False).step (float, optional) – Only returned if retstep is True
Size of spacing between samples.
See also
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.linspace(2.0, 3.0, num=5).get() array([2. , 2.25, 2.5 , 2.75, 3. ])
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nums.numpy.api.creation.
loadtxt
(fname, dtype=<class 'float'>, comments='# ', delimiter=' ', converters=None, skiprows=0, usecols=None, unpack=False, ndmin=0, encoding='bytes', max_rows=None)[source] Load data from a text file.
This docstring was copied from numpy.loadtxt.
Some inconsistencies with the NumS version may exist.
Each row in the text file must have the same number of values.
- Parameters
fname (file, str, or pathlib.Path) – File, filename, or generator to read. If the filename extension is
.gz
or.bz2
, the file is first decompressed. Note that generators should return byte strings.dtype (data-type, optional) – Data-type of the resulting array; default: float. If this is a structured data-type, the resulting array will be 1-dimensional, and each row will be interpreted as an element of the array. In this case, the number of columns used must match the number of fields in the data-type.
comments (str or sequence of str, optional) – The characters or list of characters used to indicate the start of a comment. None implies no comments. For backwards compatibility, byte strings will be decoded as ‘latin1’. The default is ‘#’.
delimiter (str, optional) – The string used to separate values. For backwards compatibility, byte strings will be decoded as ‘latin1’. The default is whitespace.
converters (dict, optional) – A dictionary mapping column number to a function that will parse the column string into the desired value. E.g., if column 0 is a date string:
converters = {0: datestr2num}
. Converters can also be used to provide a default value for missing data (but see also genfromtxt):converters = {3: lambda s: float(s.strip() or 0)}
. Default: None.skiprows (int, optional) – Skip the first skiprows lines, including comments; default: 0.
usecols (int or sequence, optional) –
Which columns to read, with 0 being the first. For example,
usecols = (1,4,5)
will extract the 2nd, 5th and 6th columns. The default, None, results in all columns being read.When a single column has to be read it is possible to use an integer instead of a tuple. E.g
usecols = 3
reads the fourth column the same way asusecols = (3,)
would.unpack (bool, optional) – If True, the returned array is transposed, so that arguments may be unpacked using
x, y, z = loadtxt(...)
. When used with a structured data-type, arrays are returned for each field. Default is False.ndmin (int, optional) – The returned array will have at least ndmin dimensions. Otherwise mono-dimensional axes will be squeezed. Legal values: 0 (default), 1 or 2.
encoding (str, optional) – Encoding used to decode the inputfile. Does not apply to input streams. The special value ‘bytes’ enables backward compatibility workarounds that ensures you receive byte arrays as results if possible and passes ‘latin1’ encoded strings to converters. Override this value to receive unicode arrays and pass strings as input to converters. If set to None the system default is used. The default value is ‘bytes’.
max_rows (int, optional) – Read max_rows lines of content after skiprows lines. The default is to read all the lines.
- Returns
out – Data read from the text file.
- Return type
Notes
This function aims to be a fast reader for simply formatted files. The genfromtxt function provides more sophisticated handling of, e.g., lines with missing values.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> from io import StringIO >>> c = StringIO("0 1\n2 3") >>> nps.loadtxt(c).get() array([[0., 1.], [2., 3.]])
>>> c = StringIO("1,0,2\n3,0,4") >>> x, y = nps.loadtxt(c, delimiter=',', usecols=(0, 2), unpack=True) >>> x.get() array([1., 3.]) >>> y.get() array([2., 4.])
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nums.numpy.api.creation.
logspace
(start, stop, num=50, endpoint=True, base=10.0, dtype=None, axis=0)[source] Return numbers spaced evenly on a log scale.
This docstring was copied from numpy.logspace.
Some inconsistencies with the NumS version may exist.
In linear space, the sequence starts at
base ** start
(base to the power of start) and ends withbase ** stop
(see endpoint below).- Parameters
start (BlockArray) –
base ** start
is the starting value of the sequence.stop (BlockArray) –
base ** stop
is the final value of the sequence, unless endpoint is False. In that case,num + 1
values are spaced over the interval in log-space, of which all but the last (a sequence of length num) are returned.num (integer, optional) – Number of samples to generate. Default is 50.
endpoint (boolean, optional) – If true, stop is the last sample. Otherwise, it is not included. Default is True.
base (float, optional) – The base of the log space. The step size between the elements in
ln(samples) / ln(base)
(orlog_base(samples)
) is uniform. Default is 10.0.dtype (dtype) – The type of the output array. If dtype is not given, infer the data type from the other input arguments.
axis (int, optional) –
The axis in the result to store the samples. Relevant only if start or stop are array-like. By default (0), the samples will be along a new axis inserted at the beginning. Use -1 to get an axis at the end.
New in version 1.16.0.
- Returns
samples – num samples, equally spaced on a log scale.
- Return type
See also
Notes
Logspace is equivalent to the code
>>> y = nps.linspace(start, stop, num=num, endpoint=endpoint) ... >>> power(base, y).astype(dtype) ...
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.logspace(2.0, 3.0, num=4).get() array([ 100. , 215.443469 , 464.15888336, 1000. ]) >>> nps.logspace(2.0, 3.0, num=4, base=2.0).get() array([4. , 5.0396842 , 6.34960421, 8. ])
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nums.numpy.api.creation.
ones
(shape, dtype=<class 'float'>)[source] Return a new array of given shape and type, filled with ones.
This docstring was copied from numpy.ones.
Some inconsistencies with the NumS version may exist.
- Parameters
shape (int or sequence of ints) – Shape of the new array, e.g.,
(2, 3)
or2
.dtype (data-type, optional) – The desired data-type for the array, e.g., int. Default is float.
- Returns
out – Array of ones with the given shape and dtype.
- Return type
See also
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.ones(5).get() array([1., 1., 1., 1., 1.])
>>> nps.ones((5,), dtype=int).get() array([1, 1, 1, 1, 1])
>>> nps.ones((2, 1)).get() array([[1.], [1.]])
>>> s = (2,2) >>> nps.ones(s).get() array([[1., 1.], [1., 1.]])
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nums.numpy.api.creation.
ones_like
(prototype, dtype=None, order='K', shape=None)[source] Return an array of ones with the same shape and type as a given array.
This docstring was copied from numpy.ones_like.
Some inconsistencies with the NumS version may exist.
- Parameters
prototype (array_like) – The shape and data-type of a define these same attributes of the returned array.
dtype (data-type, optional) – Overrides the data type of the result.
order ({'C', 'F', 'A', or 'K'}, optional) – Overrides the memory layout of the result. ‘C’ means C-order, ‘F’ means F-order, ‘A’ means ‘F’ if a is Fortran contiguous, ‘C’ otherwise. ‘K’ means match the layout of a as closely as possible.
shape (int or sequence of ints, optional.) – Overrides the shape of the result. If order=’K’ and the number of dimensions is unchanged, will try to keep order, otherwise, order=’C’ is implied.
- Returns
out – Array of ones with the same shape and type as a.
- Return type
See also
empty_like
Return an empty array with shape and type of input.
zeros_like
Return an array of zeros with shape and type of input.
full_like
Return a new array with shape of input filled with value.
ones
Return a new array setting values to one.
Notes
Only order=’K’ is supported.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> x = nps.arange(6) >>> x = x.reshape((2, 3)) >>> x.get() array([[0, 1, 2], [3, 4, 5]]) >>> nps.ones_like(x).get() array([[1, 1, 1], [1, 1, 1]])
>>> y = nps.arange(3, dtype=float) >>> y.get() array([0., 1., 2.]) >>> nps.ones_like(y).get() array([1., 1., 1.])
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nums.numpy.api.creation.
zeros
(shape, dtype=<class 'float'>)[source] Return a new array of given shape and type, without initializing entries.
This docstring was copied from numpy.zeros.
Some inconsistencies with the NumS version may exist.
Return a new array of given shape and type, filled with zeros.
- Parameters
shape (int or tuple of ints) – Shape of the new array, e.g.,
(2, 3)
or2
.dtype (data-type, optional) – The desired data-type for the array, e.g., int. Default is float.
- Returns
out – Array of zeros with the given shape and dtype.
- Return type
See also
zeros_like
Return an array of zeros with shape and type of input.
empty
Return a new uninitialized array.
ones
Return a new array setting values to one.
full
Return a new array of given shape filled with value.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> nps.zeros(5).get() array([ 0., 0., 0., 0., 0.])
>>> nps.zeros((5,), dtype=int).get() array([0, 0, 0, 0, 0])
>>> nps.zeros((2, 1)).get() array([[ 0.], [ 0.]])
>>> s = (2,2) >>> nps.zeros(s).get() array([[ 0., 0.], [ 0., 0.]])
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nums.numpy.api.creation.
zeros_like
(prototype, dtype=None, order='K', shape=None)[source] Return an array of zeros with the same shape and type as a given array.
This docstring was copied from numpy.zeros_like.
Some inconsistencies with the NumS version may exist.
- Parameters
prototype (array_like) – The shape and data-type of prototype define these same attributes of the returned array.
dtype (data-type, optional) – Overrides the data type of the result.
order ({'C', 'F', 'A', or 'K'}, optional) – Overrides the memory layout of the result. ‘C’ means C-order, ‘F’ means F-order, ‘A’ means ‘F’ if a is Fortran contiguous, ‘C’ otherwise. ‘K’ means match the layout of a as closely as possible.
shape (int or sequence of ints, optional.) – Overrides the shape of the result. If order=’K’ and the number of dimensions is unchanged, will try to keep order, otherwise, order=’C’ is implied.
- Returns
out – Array of zeros with the same shape and type as prototype.
- Return type
See also
empty_like
Return an empty array with shape and type of input.
ones_like
Return an array of ones with shape and type of input.
full_like
Return a new array with shape of input filled with value.
zeros
Return a new array setting values to zero.
Notes
Only order=’K’ is supported.
Examples
The doctests shown below are copied from NumPy. They won’t show the correct result until you operate
get()
.>>> x = nps.arange(6) >>> x = x.reshape((2, 3)) >>> x.get() array([[0, 1, 2], [3, 4, 5]]) >>> nps.zeros_like(x).get() array([[0, 0, 0], [0, 0, 0]])
>>> y = nps.arange(3, dtype=float) >>> y.get() array([0., 1., 2.]) >>> nps.zeros_like(y).get() array([0., 0., 0.])