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SCAL[α,x]

computes the scaled vector α x and resets x 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`

SCAL

SCAL[α,x]

computes the scaled vector α x and resets x to the result.

更多信息和选项

  • To use SCAL, you first need to load the BLAS Package using Needs["LinearAlgebra`BLAS`"].
  • The following arguments must be given:
  • αinput expressionscalar multiple
    xinput/output symbolvector; the symbol value is modified in place
  • SCAL[α,x] is equivalent to x=α x.

范例

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基本范例  (1)

Load the BLAS package:

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

Scale a vector by a scalar:

Wolfram Language code: x = {1, 2, 3}; SCAL[1 / 2, x]; x

Scope  (4)

A real vector:

Wolfram Language code: x = {1.2, -3.8, 2.4}; SCAL[0.3, x]; x

A complex vector:

Wolfram Language code: x = {1.2 + 3.I, 2.3I, 4.3 - I}; SCAL[2. + 0.4I, x]; x

An arbitrary-precision vector:

Wolfram Language code: x = {1`20, 2, 3}; SCAL[1`20 / 2, x]; x

A symbolic vector:

Wolfram Language code: x = {v1, v2, v3}; SCAL[α, x]; x

Properties & Relations  (1)

SCAL[α,x] is equivalent to x=α x:

Wolfram Language code: x = x1 = RandomComplex[1 + I, {5}]; α = RandomReal[1]; SCAL[α, x]; x == α x1

Possible Issues  (2)

The second argument must be a symbol:

Wolfram Language code: SCAL[1 / 2, {1, 2, 3}]

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

Wolfram Language code: Clear[x]; SCAL[1 / 2, x]
Wolfram Research (2017)，SCAL，Wolfram 语言函数，https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/SCAL.html.

文本

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

CMS

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

APA

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

BibTeX

@misc{reference.wolfram_2026_scal, author="Wolfram Research", title="{SCAL}", year="2017", howpublished="\url{https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/SCAL.html}", note=[Accessed: 11-September-2026]}

BibLaTeX

@online{reference.wolfram_2026_scal, organization={Wolfram Research}, title={SCAL}, year={2017}, url={https://reference.wolfram.com/language/LowLevelLinearAlgebra/ref/SCAL.html}, note=[Accessed: 11-September-2026]}