HeaderDisplayFunction

HeaderDisplayFunction

is an option for Dataset that specifies a function to apply to headers before displaying them.

Details

  • The setting for HeaderDisplayFunction can be any pure function.
  • With the option HeaderDisplayFunctionf, the specified function will be applied to all headers in the dataset before displaying them.
  • With the option HeaderDisplayFunctionf, the displayed header is given by f[header,position,dataset].
  • The settings for HeaderDisplayFunction can be given as follows to apply separately to different items:
  • specapply spec to all headers
    {spec1,spec2,,specn}apply speck to headers at dataset level k
    {spec_(1),spec_(2),...,spec_(n), rules}also allow explicit rules for individual headers
  • The speck can have the following forms:
  • {s1,s2,,sn}use s1 through sn; then use defaults
    {{c}}use c in all cases
    {{c1,c2}}alternate between c1 and c2
    {{c1,c2,}}cycle through all ci
    {s,{c}}use s, then repeatedly use c
    {s1,{c},sn}use s1, then repeatedly use c, but use sn at the end
    {s1,s2,,{c1,c2,},sm,,sn} use the first sequence of si at the beginning, then cyclically use the ci, then use the last sequence of si at the end
    {s1,s2,,{},sm,,sn}use the first sequence of si at the beginning and the last sequence at the end
  • Rules have the form ispec, where i specifies a position in the dataset.
  • Positions can be patterns.
  • The position of a header can be read at the bottom of a dataset when you hover over the header.
  • If the left-hand side of a rule is not a list, the setting is applied to any position that contains the left-hand side as a key or index.

Examples

open allclose all

Basic Examples  (1)

Make all headers lowercase:

Possible Issues  (1)

The value of HeaderDisplayFunction must be an explicit pure function. Other values will have no effect:

Use an explicit pure function:

Wolfram Research (2020), HeaderDisplayFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/HeaderDisplayFunction.html.

Text

Wolfram Research (2020), HeaderDisplayFunction, Wolfram Language function, https://reference.wolfram.com/language/ref/HeaderDisplayFunction.html.

BibTeX

@misc{reference.wolfram_2020_headerdisplayfunction, author="Wolfram Research", title="{HeaderDisplayFunction}", year="2020", howpublished="\url{https://reference.wolfram.com/language/ref/HeaderDisplayFunction.html}", note=[Accessed: 03-December-2020 ]}

BibLaTeX

@online{reference.wolfram_2020_headerdisplayfunction, organization={Wolfram Research}, title={HeaderDisplayFunction}, year={2020}, url={https://reference.wolfram.com/language/ref/HeaderDisplayFunction.html}, note=[Accessed: 03-December-2020 ]}

CMS

Wolfram Language. 2020. "HeaderDisplayFunction." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/HeaderDisplayFunction.html.

APA

Wolfram Language. (2020). HeaderDisplayFunction. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/HeaderDisplayFunction.html