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AXPY[α,x,y]

computes the vector y+αx and resets y to the result.

更多信息和选项
Details and Options Details and Options
范例  
基本范例  
Scope  
Properties & Relations  
Possible Issues  
相关指南
按以下格式引用：
LinearAlgebra`BLAS`
LinearAlgebra`BLAS`

AXPY

AXPY[α,x,y]

computes the vector y+αx and resets y to the result.

更多信息和选项

  • To use AXPY, you first need to load the BLAS Package using Needs["LinearAlgebra`BLAS`"].
  • The following arguments must be given:
  • αinput expressionscalar multiple
    xinput expressionvector
    yinput/output symbolvector; the symbol value is modified in place
  • Dimensions of the vector arguments must be such that the addition is well defined.

范例

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基本范例  (1)

Load the BLAS package:

Wolfram Language code: Needs["LinearAlgebra`BLAS`"]

Compute y=2{1,2,3}+y:

Wolfram Language code: y = {-1, 2, 1}; AXPY[2, {1, 2, 3}, y]; y

Scope  (4)

Real vectors:

Wolfram Language code: y = {3.2, -1.6, 2.9}; AXPY[2.2, {-1.5, -2.4, 4.1}, y]; y

Complex vectors:

Wolfram Language code: z = {1.2 + 0.4 I, 2.1 - 1.1 I}; AXPY[2.5, {-I, 2.3}, z]; z

Arbitrary-precision vectors:

Wolfram Language code: y = {-1`20, 2, 1}; AXPY[2`20, {1, 2, 3}, y]; y

Symbolic vectors:

Wolfram Language code: s = {a, b, c}; AXPY[β, {d, e, f}, s]; s

Properties & Relations  (1)

AXPY[α,x,y] is equivalent to assigned to :

Wolfram Language code: y1 = y = RandomReal[1, {5}]; x = RandomReal[1, {5}]; α = RandomReal[1]; AXPY[α, x, y]; y == y1 + α x

Possible Issues  (2)

The third argument must be a symbol:

Wolfram Language code: AXPY[2, {1, 2, 3}, {-1, 2, 1}]

If the third argument is not initialized, an error message is issued:

Wolfram Language code: AXPY[2, {1, 2, 3}, w]
Wolfram Research (2017)，AXPY，Wolfram 语言函数，https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/AXPY.html.

文本

Wolfram Research (2017)，AXPY，Wolfram 语言函数，https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/AXPY.html.

CMS

Wolfram 语言. 2017. "AXPY." Wolfram 语言与系统参考资料中心. Wolfram Research. https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/AXPY.html.

APA

Wolfram 语言. (2017). AXPY. Wolfram 语言与系统参考资料中心. 追溯自 https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/AXPY.html 年

BibTeX

@misc{reference.wolfram_2026_axpy, author="Wolfram Research", title="{AXPY}", year="2017", howpublished="\url{https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/AXPY.html}", note=[Accessed: 08-September-2026]}

BibLaTeX

@online{reference.wolfram_2026_axpy, organization={Wolfram Research}, title={AXPY}, year={2017}, url={https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/AXPY.html}, note=[Accessed: 08-September-2026]}