Source code for xorbits._mars.tensor.linalg.vdot
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from ..datasource import tensor as astensor
from .dot import dot
[docs]def vdot(a, b):
"""
Return the dot product of two vectors.
The vdot(`a`, `b`) function handles complex numbers differently than
dot(`a`, `b`). If the first argument is complex the complex conjugate
of the first argument is used for the calculation of the dot product.
Note that `vdot` handles multidimensional tensors differently than `dot`:
it does *not* perform a matrix product, but flattens input arguments
to 1-D vectors first. Consequently, it should only be used for vectors.
Parameters
----------
a : array_like
If `a` is complex the complex conjugate is taken before calculation
of the dot product.
b : array_like
Second argument to the dot product.
Returns
-------
output : Tensor
Dot product of `a` and `b`. Can be an int, float, or
complex depending on the types of `a` and `b`.
See Also
--------
dot : Return the dot product without using the complex conjugate of the
first argument.
Examples
--------
>>> import mars.tensor as mt
>>> a = mt.array([1+2j,3+4j])
>>> b = mt.array([5+6j,7+8j])
>>> mt.vdot(a, b).execute()
(70-8j)
>>> mt.vdot(b, a).execute()
(70+8j)
Note that higher-dimensional arrays are flattened!
>>> a = mt.array([[1, 4], [5, 6]])
>>> b = mt.array([[4, 1], [2, 2]])
>>> mt.vdot(a, b).execute()
30
>>> mt.vdot(b, a).execute()
30
>>> 1*4 + 4*1 + 5*2 + 6*2
30
"""
a, b = astensor(a), astensor(b)
return dot(a.conj().ravel(), b.ravel())