is an option to Refresh, Manipulate, and related functions that specifies which symbols should trigger updates when their values are changed.


  • The following settings can be used:
  • Allall possible symbols
    Fullsymbols that appear explicitly in the input expression
    Truesymbols that appear in Manipulate, etc. controls
    Automaticsymbols being tracked in enclosing constructs
    {x,y,z,}an explicit list of symbols
  • When a list of symbols is given, the typical usage is TrackedSymbols:>{x,y,z,}.


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Basic Examples  (1)

Specify symbols in Manipulate that will be used for updating:

Possible Issues  (2)

Symbols in an explicit list will not be tracked if they were not evaluated in the enclosing construct:

Using Rule for TrackedSymbols fails in some cases because the symbols are evaluated:

Generally, RuleDelayed should always be used for TrackedSymbols:

Introduced in 2007
Updated in 2008