is an option for notebooks, cells, Dynamic, DynamicModule, Manipulate and related constructs that specifies an expression to be evaluated when the construct is first displayed.
- The typical usage is Initialization:>expr.
- Initialization expressions defined in particular cells in a notebook are evaluated when those cells are first made visible, and not necessarily when the notebook is first opened.
- Initialization expressions are guaranteed to be evaluated exactly once before the contents of the main construct are resolved.
- An object that is already initialized can be initialized again if it is deleted, then restored as a result of using Undo. If an object is copied and pasted, each pasted copy will initialize again.
- Initialization expressions may be applied directly to notebooks and cells. Unlike most other option values, the Initialization option of a cell will not inherit any settings applied at the notebook level.
Examplesopen allclose all
Basic Examples (4)
Specify an expression to be evaluated before displaying Dynamic:
Properties & Relations (3)
Initialization is guaranteed to only happen once:
Initialization for outer constructs occurs before initialization for inner constructs:
Each time a Dynamic destroys and recreates an initializing construct, the initialization will run again:
Possible Issues (3)
Loading a package in the initialization does not allow you to use unqualified symbols from that package:
Doing this properly requires loading the package in the Input cell and loading it in an outer initialization:
This function produces a cell indicating the current Initialization setting upon that cell:
Unlike most options, cells do not inherit Initialization from the notebook setting:
Cells still inherit Initialization from named cell styles:
Wolfram Research (2007), Initialization, Wolfram Language function, https://reference.wolfram.com/language/ref/Initialization.html (updated 2020).
Wolfram Language. 2007. "Initialization." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2020. https://reference.wolfram.com/language/ref/Initialization.html.
Wolfram Language. (2007). Initialization. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Initialization.html