Indexed

Indexed[expr,i]

represents the component of expr with index i and formats as expri.

Indexed[expr,{i,j,}]

represents the component with indices i, j, and formats as expri,j,.

Details

  • Indexed can be used to indicate components of symbolic vectors, matrices, tensors, etc.
  • When expr is a list, Indexed[expr,i] gives expr[[i]].
  • When expr is a list, Indexed[expr,{i,j,}] gives Indexed[expr[[i]],{j,}].

Examples

Basic Examples  (3)

Represent part 1 of a symbolic vector x:

For a concrete vector, it extracts the part:

Represent part 1,2 in a symbolic matrix x:

For a concrete matrix, it extracts the part:

Use Indexed to work with symbolic vector variables:

Wolfram Research (2014), Indexed, Wolfram Language function, https://reference.wolfram.com/language/ref/Indexed.html.

Text

Wolfram Research (2014), Indexed, Wolfram Language function, https://reference.wolfram.com/language/ref/Indexed.html.

BibTeX

@misc{reference.wolfram_2021_indexed, author="Wolfram Research", title="{Indexed}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/Indexed.html}", note=[Accessed: 22-October-2021 ]}

BibLaTeX

@online{reference.wolfram_2021_indexed, organization={Wolfram Research}, title={Indexed}, year={2014}, url={https://reference.wolfram.com/language/ref/Indexed.html}, note=[Accessed: 22-October-2021 ]}

CMS

Wolfram Language. 2014. "Indexed." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Indexed.html.

APA

Wolfram Language. (2014). Indexed. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Indexed.html