Array object

Array API specification for array object attributes and methods.

A conforming implementation of the array API standard must provide and support an array object having the following attributes and methods adhering to the following conventions.

  • Positional parameters must be positional-only parameters. Positional-only parameters have no externally-usable name. When a method accepting positional-only parameters is called, positional arguments are mapped to these parameters based solely on their order.

  • Optional parameters must be keyword-only arguments.

  • Broadcasting semantics must follow the semantics defined in Broadcasting .

  • Unless stated otherwise, methods must support the data types defined in Data Types .

  • Unless stated otherwise, methods must adhere to the type promotion rules defined in Type Promotion Rules .

  • Unless stated otherwise, floating-point operations must adhere to IEEE 754-2019.


Operators

A conforming implementation of the array API standard must provide and support an array object supporting the following Python operators:

In-place Operators

A conforming implementation of the array API standard must provide and support an array object supporting the following in-place Python operators:

  • += . May be implemented via __iadd__ .

  • -= . May be implemented via __isub__ .

  • *= . May be implemented via __imul__ .

  • /= . May be implemented via __itruediv__ .

  • //= . May be implemented via __ifloordiv__ .

  • **= . May be implemented via __ipow__ .

  • @= . May be implemented via __imatmul__ .

  • %= . May be implemented via __imod__ .

  • &= . May be implemented via __iand__ .

  • |= . May be implemented via __ior__ .

  • ^= . May be implemented via __ixor__ .

  • <<= . May be implemented via __ilshift__ .

  • >>= . May be implemented via __irshift__ .

An in-place operation must not change the dtype or shape of the in-place array as a result of Type Promotion Rules or Broadcasting .

Note

In-place operators must be supported as discussed in Copy-view behaviour and mutability .

Reflected Operators

A conforming implementation of the array API standard must provide and support an array object supporting the following reflected operators:

  • __radd__

  • __rsub__

  • __rmul__

  • __rtruediv__

  • __rfloordiv__

  • __rpow__

  • __rmatmul__

  • __rmod__

  • __rand__

  • __ror__

  • __rxor__

  • __rlshift__

  • __rrshift__

The results of applying reflected operators must match their non-reflected equivalents.

Note

All operators for which array <op> scalar is implemented must have an equivalent reflected operator implementation.


Attributes

dtype

Data type of the array elements.

Returns

  • out : <dtype>

    • array data type.

device

Hardware device the array data resides on.

Returns

mT

Transpose of a matrix (or a stack of matrices).

If an array instance has fewer than two dimensions, an error should be raised.

Returns

  • out : <array>

    • array whose last two dimensions (axes) are permuted in reverse order relative to original array (i.e., for an array instance having shape (..., M, N) , the returned array must have shape (..., N, M) ). The returned array must have the same data type as the original array.

ndim

Number of array dimensions (axes).

Returns

  • out : int

    • number of array dimensions (axes).

TODO: need to more carefully consider this in order to accommodate, e.g., graph tensors where the number of dimensions may be dynamic.

shape

Array dimensions.

Returns

  • out : Union[ Tuple[ int, …], <shape> ]

    • array dimensions as either a tuple or a custom shape object. If a shape object, the object must be immutable and must support indexing for dimension retrieval.

TODO: need to more carefully consider this in order to accommodate, e.g., graph tensors where a shape may be dynamic.

size

Number of elements in an array. This must equal the product of the array’s dimensions.

Returns

  • out : int

    • number of elements in an array.

TODO: need to more carefully consider this in order to accommodate, e.g., graph tensors where the number of elements may be dynamic.

T

Transpose of the array.

The array instance must be two-dimensional. If the array instance is not two-dimensional, an error should be raised.

Note

Limiting the transpose to two-dimensional arrays (matrices) deviates from the NumPy et al practice of reversing all axes for arrays having more than two-dimensions. This is intentional, as reversing all axes was found to be problematic (e.g., conflicting with the mathematical definition of a transpose which is limited to matrices; not operating on batches of matrices; et cetera). In order to reverse all axes, one is recommended to use the functional permute_dims interface found in this specification.

Returns

  • out : <array>

    • two-dimensional array whose first and last dimensions (axes) are permuted in reverse order relative to original array. The returned array must have the same data type as the original array.


Methods

__abs__(self, /)

Calculates the absolute value for each element of an array instance (i.e., the element-wise result has the same magnitude as the respective element but has positive sign).

Note

For signed integer data types, the absolute value of the minimum representable integer is implementation-dependent.

Special Cases

For floating-point operands, let self equal x .

  • If x_i is NaN , the result is NaN .

  • If x_i is -0 , the result is +0 .

  • If x_i is -infinity , the result is +infinity .

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise absolute value. The returned array must have the same data type as self .

Note

Element-wise results must equal the results returned by the equivalent element-wise function abs(x) .

__add__(self, other, /)

Calculates the sum for each element of an array instance with the respective element of the array other .

Special Cases

For floating-point operands, let self equal x1 and other equal x2 .

  • If either x1_i or x2_i is NaN , the result is NaN .

  • If x1_i is +infinity and x2_i is -infinity , the result is NaN .

  • If x1_i is -infinity and x2_i is +infinity , the result is NaN .

  • If x1_i is +infinity and x2_i is +infinity , the result is +infinity .

  • If x1_i is -infinity and x2_i is -infinity , the result is -infinity .

  • If x1_i is +infinity and x2_i is a finite number, the result is +infinity .

  • If x1_i is -infinity and x2_i is a finite number, the result is -infinity .

  • If x1_i is a finite number and x2_i is +infinity , the result is +infinity .

  • If x1_i is a finite number and x2_i is -infinity , the result is -infinity .

  • If x1_i is -0 and x2_i is -0 , the result is -0 .

  • If x1_i is -0 and x2_i is +0 , the result is +0 .

  • If x1_i is +0 and x2_i is -0 , the result is +0 .

  • If x1_i is +0 and x2_i is +0 , the result is +0 .

  • If x1_i is either +0 or -0 and x2_i is a nonzero finite number, the result is x2_i .

  • If x1_i is a nonzero finite number and x2_i is either +0 or -0 , the result is x1_i .

  • If x1_i is a nonzero finite number and x2_i is -x1_i , the result is +0 .

  • In the remaining cases, when neither infinity , +0 , -0 , nor a NaN is involved, and the operands have the same mathematical sign or have different magnitudes, the sum must be computed and rounded to the nearest representable value according to IEEE 754-2019 and a supported round mode. If the magnitude is too large to represent, the operation overflows and the result is an infinity of appropriate mathematical sign.

Note

Floating-point addition is a commutative operation, but not always associative.

Parameters

  • self : <array>

    • array instance (augend array). Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • addend array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise sums. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function add(x1, x2) .

__and__(self, other, /)

Evaluates self_i & other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have an integer or boolean data type.

  • other : Union[ int, bool, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have an integer or boolean data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function bitwise_and(x1, x2) .

__array_namespace__(self, /, *, api_version=None)

Returns an object that has all the array API functions on it.

Parameters

  • self : <array>

    • array instance.

  • api_version : <Optional[str]>

    • string representing the version of the array API specification to be returned, in 'YYYY.MM' form, for example, '2020.10' . If it is None , it should return the namespace corresponding to latest version of the array API specification. If the given version is invalid or not implemented for the given module, an error should be raised. Default: None .

Returns

  • out : <object>

    • an object representing the array API namespace. It should have every top-level function defined in the specification as an attribute. It may contain other public names as well, but it is recommended to only include those names that are part of the specification.

__bool__(self, /)

Converts a zero-dimensional boolean array to a Python bool object.

Parameters

  • self : <array>

    • zero-dimensional array instance. Must have a boolean data type.

Returns

  • out : <bool>

    • a Python bool object representing the single element of the array.

__dlpack__(self, /, *, stream=None)

Exports the array for consumption by from_dlpack(x, /) as a DLPack capsule.

Parameters

  • self : <array>

    • array instance.

  • stream : Optional[ Union[ int, Any ]]

    • for CUDA and ROCm, a Python integer representing a pointer to a stream, on devices that support streams. stream is provided by the consumer to the producer to instruct the producer to ensure that operations can safely be performed on the array (e.g., by inserting a dependency between streams via “wait for event”). The pointer must be a positive integer or -1 . If stream is -1 , the value may be used by the consumer to signal “producer must not perform any synchronization”. The ownership of the stream stays with the consumer.

      On CPU and other device types without streams, only None is accepted.

      For other device types which do have a stream, queue or similar synchronization mechanism, the most appropriate type to use for stream is not yet determined. E.g., for SYCL one may want to use an object containing an in-order cl::sycl::queue . This is allowed when libraries agree on such a convention, and may be standardized in a future version of this API standard.

      Device-specific notes:

      CUDA

      • None : producer must assume the legacy default stream (default).

      • 1 : the legacy default stream.

      • 2 : the per-thread default stream.

      • > 2 : stream number represented as a Python integer.

      0 is disallowed due to its ambiguity: 0 could mean either None , 1 , or 2 .

      ROCm

      • None : producer must assume the legacy default stream (default).

      • 0 : the default stream.

      • > 2 : stream number represented as a Python integer.

      Using 1 and 2 is not supported.

      Tip

      It is recommended that implementers explicitly handle streams. If they use the legacy default stream, specifying 1 (CUDA) or 0 (ROCm) is preferred. None is a safe default for developers who do not want to think about stream handling at all, potentially at the cost of more synchronization than necessary.

Returns

__dlpack_device__(self, /)

Returns device type and device ID in DLPack format. Meant for use within from_dlpack(x, /) .

Parameters

  • self : <array>

    • array instance.

Returns

  • device : Tuple[enum.IntEnum, int]

    • a tuple (device_type, device_id) in DLPack format. Valid device type enum members are:

      CPU = 1
      CUDA = 2
      CPU_PINNED = 3
      OPENCL = 4
      VULKAN = 7
      METAL = 8
      VPI = 9
      ROCM = 10
      

__eq__(self, other, /)

Computes the truth value of self_i == other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. May have any data type.

  • other : Union[ int, float, bool, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). May have any data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type of bool .

Note

Element-wise results must equal the results returned by the equivalent element-wise function equal(x1, x2) .

__float__(self, /)

Converts a zero-dimensional floating-point array to a Python float object.

Parameters

  • self : <array>

    • zero-dimensional array instance. Must have a floating-point data type.

Returns

  • out : <float>

    • a Python float object representing the single element of the array instance.

__floordiv__(self, other, /)

Evaluates self_i // other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function floor_divide(x1, x2) .

__ge__(self, other, /)

Computes the truth value of self_i >= other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type of bool .

Note

Element-wise results must equal the results returned by the equivalent element-wise function greater_equal(x1, x2) .

__getitem__(self, key, /)

Returns self[key] .

Parameters

  • self : <array>

    • array instance.

  • key : Union[ int, slice, ellipsis, Tuple[ Union[ int, slice, ellipsis ], … ], <array> ]

    • index key.

Returns

  • out : <array>

    • an array containing the accessed value(s). The returned array must have the same data type as self .

__gt__(self, other, /)

Computes the truth value of self_i > other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type of bool .

Note

Element-wise results must equal the results returned by the equivalent element-wise function greater(x1, x2) .

__index__(self, /)

Converts a zero-dimensional integer array to a Python int object.

Note

This method is called to implement operator.index() . See also PEP 357 .

Parameters

  • self : <array>

    • zero-dimensional array instance. Must have an integer data type.

Returns

  • out : <int>

    • a Python int object representing the single element of the array instance.

__int__(self, /)

Converts a zero-dimensional integer array to a Python int object.

Parameters

  • self : <array>

    • zero-dimensional array instance. Must have an integer data type.

Returns

  • out : <int>

    • a Python int object representing the single element of the array instance.

__invert__(self, /)

Evaluates ~self_i for each element of an array instance.

Parameters

  • self : <array>

    • array instance. Should have an integer or boolean data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have the same data type as self .

Note

Element-wise results must equal the results returned by the equivalent element-wise function bitwise_invert(x) .

__le__(self, other, /)

Computes the truth value of self_i <= other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type of bool .

Note

Element-wise results must equal the results returned by the equivalent element-wise function less_equal(x1, x2) .

__len__(self, /)

TODO: need to more carefully consider this in order to accommodate, e.g., graph tensors where a shape may be dynamic. Furthermore, not clear whether this should be implemented, as, e.g., NumPy’s behavior of returning the size of the first dimension is not necessarily intuitive, as opposed to, say, the total number of elements.

__lshift__(self, other, /)

Evaluates self_i << other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have an integer data type.

  • other : Union[ int, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have an integer data type. Each element must be greater than or equal to 0 .

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have the same data type as self .

Note

Element-wise results must equal the results returned by the equivalent element-wise function bitwise_left_shift(x1, x2) .

__lt__(self, other, /)

Computes the truth value of self_i < other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type of bool .

Note

Element-wise results must equal the results returned by the equivalent element-wise function less(x1, x2) .

__matmul__(self, other, /)

Computes the matrix product.

Note

The matmul function must implement the same semantics as the built-in @ operator (see PEP 465 ).

Parameters

  • self : <array>

    • array instance. Should have a numeric data type. Must have at least one dimension. If self is one-dimensional having shape (M) and other has more than one dimension, self must be promoted to a two-dimensional array by prepending 1 to its dimensions (i.e., must have shape (1, M) ). After matrix multiplication, the prepended dimensions in the returned array must be removed. If self has more than one dimension (including after vector-to-matrix promotion), self must be compatible with other (see Broadcasting ). If self has shape (..., M, K) , the innermost two dimensions form matrices on which to perform matrix multiplication.

  • other : <array>

    • other array. Should have a numeric data type. Must have at least one dimension. If other is one-dimensional having shape (N) and self has more than one dimension, other must be promoted to a two-dimensional array by appending 1 to its dimensions (i.e., must have shape (N, 1) ). After matrix multiplication, the appended dimensions in the returned array must be removed. If other has more than one dimension (including after vector-to-matrix promotion), other must be compatible with self (see Broadcasting ). If other has shape (..., K, N) , the innermost two dimensions form matrices on which to perform matrix multiplication.

Returns

  • out : <array>

    • if both self and other are one-dimensional arrays having shape (N) , a zero-dimensional array containing the inner product as its only element.

    • if self is a two-dimensional array having shape (M, K) and other is a two-dimensional array having shape (K, N) , a two-dimensional array containing the conventional matrix product and having shape (M, N) .

    • if self is a one-dimensional array having shape (K) and other is an array having shape (..., K, N) , an array having shape (..., N) (i.e., prepended dimensions during vector-to-matrix promotion must be removed) and containing the conventional matrix product .

    • if self is an array having shape (..., M, K) and other is a one-dimensional array having shape (K) , an array having shape (..., M) (i.e., appended dimensions during vector-to-matrix promotion must be removed) and containing the conventional matrix product .

    • if self is a two-dimensional array having shape (M, K) and other is an array having shape (..., K, N) , an array having shape (..., M, N) and containing the conventional matrix product for each stacked matrix.

    • if self is an array having shape (..., M, K) and other is a two-dimensional array having shape (K, N) , an array having shape (..., M, N) and containing the conventional matrix product for each stacked matrix.

    • if either self or other has more than two dimensions, an array having a shape determined by Broadcasting self against other and containing the conventional matrix product for each stacked matrix.

    The returned array must have a data type determined by Type Promotion Rules .

    Note

    Results must equal the results returned by the equivalent function matmul(x1, x2) .

Raises

  • if either self or other is a zero-dimensional array.

  • if self is a one-dimensional array having shape (N) , other is a one-dimensional array having shape (M) , and N != M .

  • if self is an array having shape (..., M, K) , other is an array having shape (..., L, N) , and K != L .

__mod__(self, other, /)

Evaluates self_i % other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. Each element-wise result must have the same sign as the respective element other_i . The returned array must have a floating-point data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function remainder(x1, x2) .

__mul__(self, other, /)

Calculates the product for each element of an array instance with the respective element of the array other .

Special Cases

For floating-point operands, let self equal x1 and other equal x2 .

  • If either x1_i or x2_i is NaN , the result is NaN .

  • If x1_i is either +infinity or -infinity and x2_i is either +0 or -0 , the result is NaN .

  • If x1_i is either +0 or -0 and x2_i is either +infinity or -infinity , the result is NaN .

  • If x1_i and x2_i have the same mathematical sign, the result has a positive mathematical sign, unless the result is NaN . If the result is NaN , the “sign” of NaN is implementation-defined.

  • If x1_i and x2_i have different mathematical signs, the result has a negative mathematical sign, unless the result is NaN . If the result is NaN , the “sign” of NaN is implementation-defined.

  • If x1_i is either +infinity or -infinity and x2_i is either +infinity or -infinity , the result is a signed infinity with the mathematical sign determined by the rule already stated above.

  • If x1_i is either +infinity or -infinity and x2_i is a nonzero finite number, the result is a signed infinity with the mathematical sign determined by the rule already stated above.

  • If x1_i is a nonzero finite number and x2_i is either +infinity or -infinity , the result is a signed infinity with the mathematical sign determined by the rule already stated above.

  • In the remaining cases, where neither infinity nor NaN is involved, the product must be computed and rounded to the nearest representable value according to IEEE 754-2019 and a supported rounding mode. If the magnitude is too large to represent, the result is an infinity of appropriate mathematical sign. If the magnitude is too small to represent, the result is a zero of appropriate mathematical sign.

Note

Floating-point multiplication is not always associative due to finite precision.

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise products. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function multiply(x1, x2) .

__ne__(self, other, /)

Computes the truth value of self_i != other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. May have any data type.

  • other : Union[ int, float, bool, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). May have any data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type of bool (i.e., must be a boolean array).

Note

Element-wise results must equal the results returned by the equivalent element-wise function not_equal(x1, x2) .

__neg__(self, /)

Evaluates -self_i for each element of an array instance.

Note

For signed integer data types, the numerical negative of the minimum representable integer is implementation-dependent.

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the evaluated result for each element in self . The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function negative(x) .

__or__(self, other, /)

Evaluates self_i | other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have an integer or boolean data type.

  • other : Union[ int, bool, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have an integer or boolean data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function bitwise_or(x1, x2) .

__pos__(self, /)

Evaluates +self_i for each element of an array instance.

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the evaluated result for each element. The returned array must have the same data type as self .

Note

Element-wise results must equal the results returned by the equivalent element-wise function positive(x) .

__pow__(self, other, /)

Calculates an implementation-dependent approximation of exponentiation by raising each element (the base) of an array instance to the power of other_i (the exponent), where other_i is the corresponding element of the array other .

Special Cases

For floating-point operands, let self equal x1 and other equal x2 .

  • If x1_i is not equal to 1 and x2_i is NaN , the result is NaN .

  • If x2_i is +0 , the result is 1 , even if x1_i is NaN .

  • If x2_i is -0 , the result is 1 , even if x1_i is NaN .

  • If x1_i is NaN and x2_i is not equal to 0 , the result is NaN .

  • If abs(x1_i) is greater than 1 and x2_i is +infinity , the result is +infinity .

  • If abs(x1_i) is greater than 1 and x2_i is -infinity , the result is +0 .

  • If abs(x1_i) is 1 and x2_i is +infinity , the result is 1 .

  • If abs(x1_i) is 1 and x2_i is -infinity , the result is 1 .

  • If x1_i is 1 and x2_i is not NaN , the result is 1 .

  • If abs(x1_i) is less than 1 and x2_i is +infinity , the result is +0 .

  • If abs(x1_i) is less than 1 and x2_i is -infinity , the result is +infinity .

  • If x1_i is +infinity and x2_i is greater than 0 , the result is +infinity .

  • If x1_i is +infinity and x2_i is less than 0 , the result is +0 .

  • If x1_i is -infinity and x2_i is greater than 0 , the result is -infinity .

  • If x1_i is -infinity , x2_i is greater than 0 , and x2_i is not an odd integer value, the result is +infinity .

  • If x1_i is -infinity , x2_i is less than 0 , and x2_i is an odd integer value, the result is -0 .

  • If x1_i is -infinity , x2_i is less than 0 , and x2_i is not an odd integer value, the result is +0 .

  • If x1_i is +0 and x2_i is greater than 0 , the result is +0 .

  • If x1_i is +0 and x2_i is less than 0 , the result is +infinity .

  • If x1_i is -0 , x2_i is greater than 0 , and x2_i is an odd integer value, the result is -0 .

  • If x1_i is -0 , x2_i is greater than 0 , and x2_i is not an odd integer value, the result is +0 .

  • If x1_i is -0 , x2_i is less than 0 , and x2_i is an odd integer value, the result is -infinity .

  • If x1_i is -0 , x2_i is less than 0 , and x2_i is not an odd integer value, the result is +infinity .

  • If x1_i is less than 0 , x1_i is a finite number, x2_i is a finite number, and x2_i is not an integer value, the result is NaN .

Parameters

  • self : <array>

    • array instance whose elements correspond to the exponentiation base. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array whose elements correspond to the exponentiation exponent. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function pow(x1, x2) .

__rshift__(self, other, /)

Evaluates self_i >> other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have an integer data type.

  • other : Union[ int, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have an integer data type. Each element must be greater than or equal to 0 .

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have the same data type as self .

Note

Element-wise results must equal the results returned by the equivalent element-wise function bitwise_right_shift(x1, x2) .

__setitem__(self, key, value, /)

Sets self[key] to value .

Parameters

  • self : <array>

    • array instance.

  • key : Union[ int, slice, ellipsis, Tuple[ Union[ int, slice, ellipsis ], … ], <array> ]

    • index key.

  • value : Union[ int, float, bool, <array> ]

    • value(s) to set. Must be compatible with self[key] (see Broadcasting ).

Note

Setting array values must not affect the data type of self .

When value is a Python scalar (i.e., int , float , bool ), behavior must follow specification guidance on mixing arrays with Python scalars (see Type Promotion Rules ).

When value is an array of a different data type than self , how values are cast to the data type of self is implementation defined.

__sub__(self, other, /)

Calculates the difference for each element of an array instance with the respective element of the array other . The result of self_i - other_i must be the same as self_i + (-other_i) and must be governed by the same floating-point rules as addition (see __add__() ).

Parameters

  • self : <array>

    • array instance (minuend array). Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • subtrahend array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise differences. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function subtract(x1, x2) .

__truediv__(self, other, /)

Evaluates self_i / other_i for each element of an array instance with the respective element of the array other .

Special Cases

For floating-point operands, let self equal x1 and other equal x2 .

  • If either x1_i or x2_i is NaN , the result is NaN .

  • If x1_i is either +infinity or -infinity and x2_i is either +infinity or -infinity , the result is NaN .

  • If x1_i is either +0 or -0 and x2_i is either +0 or -0 , the result is NaN .

  • If x1_i is +0 and x2_i is greater than 0 , the result is +0 .

  • If x1_i is -0 and x2_i is greater than 0 , the result -0 .

  • If x1_i is +0 and x2_i is less than 0 , the result is -0 .

  • If x1_i is -0 and x2_i is less than 0 , the result is +0 .

  • If x1_i is greater than 0 and x2_i is +0 , the result is +infinity .

  • If x1_i is greater than 0 and x2_i is -0 , the result is -infinity .

  • If x1_i is less than 0 and x2_i is +0 , the result is -infinity .

  • If x1_i is less than 0 and x2_i is -0 , the result is +infinity .

  • If x1_i is +infinity and x2_i is a positive (i.e., greater than 0 ) finite number, the result is +infinity .

  • If x1_i is +infinity and x2_i is a negative (i.e., less than 0 ) finite number, the result is -infinity .

  • If x1_i is -infinity and x2_i is a positive (i.e., greater than 0 ) finite number, the result is -infinity .

  • If x1_i is -infinity and x2_i is a negative (i.e., less than 0 ) finite number, the result is +infinity .

  • If x1_i is a positive (i.e., greater than 0 ) finite number and x2_i is +infinity , the result is +0 .

  • If x1_i is a positive (i.e., greater than 0 ) finite number and x2_i is -infinity , the result is -0 .

  • If x1_i is a negative (i.e., less than 0 ) finite number and x2_i is +infinity , the result is -0 .

  • If x1_i is a negative (i.e., less than 0 ) finite number and x2_i is -infinity , the result is +0 .

  • If x1_i and x2_i have the same mathematical sign and are both nonzero finite numbers, the result has a positive mathematical sign.

  • If x1_i and x2_i have different mathematical signs and are both nonzero finite numbers, the result has a negative mathematical sign.

  • In the remaining cases, where neither -infinity , +0 , -0 , nor NaN is involved, the quotient must be computed and rounded to the nearest representable value according to IEEE 754-2019 and a supported rounding mode. If the magnitude is too larger to represent, the operation overflows and the result is an infinity of appropriate mathematical sign. If the magnitude is too small to represent, the operation underflows and the result is a zero of appropriate mathematical sign.

Parameters

  • self : <array>

    • array instance. Should have a numeric data type.

  • other : Union[ int, float, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have a numeric data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function divide(x1, x2) .

__xor__(self, other, /)

Evaluates self_i ^ other_i for each element of an array instance with the respective element of the array other .

Parameters

  • self : <array>

    • array instance. Should have an integer or boolean data type.

  • other : Union[ int, bool, <array> ]

    • other array. Must be compatible with self (see Broadcasting ). Should have an integer or boolean data type.

Returns

  • out : <array>

    • an array containing the element-wise results. The returned array must have a data type determined by Type Promotion Rules .

Note

Element-wise results must equal the results returned by the equivalent element-wise function bitwise_xor(x1, x2) .

to_device(self, device, /)

Move the array to the given device.

Parameters

  • self : <array>

    • array instance.

  • device : <device>

Returns

  • out : <array>

    • an array with the same data and dtype, located on the specified device.