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Options for Cells
Mathematica provides a large number of options for cells. All of these options can be accessed through the Option Inspector menu item in the front end. They can be set either directly at the level of individual cells or at a higher level, to be inherited by individual cells.
option | typical default value | |
| CellDingbat | None | a dingbat to use to emphasize the cell |
| CellFrame | False | whether to draw a frame around the cell |
| Background | None | the background color for the cell |
| ShowCellBracket | True | whether to display the cell bracket |
| Magnification | 1. | the magnification at which to display the cell |
| CellOpen | True | whether to display the contents of the cell |
Some basic cell display options.
option | typical default value | |
| CellMargins | {{7,0},{4,4}} | outer margins in printer's points to leave around the contents of the cell |
| CellFrameMargins | 8 | margins to leave inside the cell frame |
| CellElementSpacings | list of rules | details of the layout of cell elements |
| CellBaseline | Baseline | how to align the baseline of an inline cell with text around it |
The option CellMargins allows you to specify both horizontal and vertical margins to put around a cell. You can set the horizontal margins interactively by using the margin stops in the ruler displayed when you choose the Show Ruler menu item in the front end.
Whenever an option can refer to all four edges of a cell, Mathematica follows the convention that the setting for the option takes the form 
. By giving nonzero values for the top and bottom elements, CellMargins can specify gaps to leave above and below a particular cell. The values are always taken to be in printer's points.
Almost every aspect of Mathematica notebooks can be controlled by some option or another. More detailed aspects are typically handled by "aggregate options" such as 
. The settings for these options are lists of Mathematica rules, which effectively give values for a sequence of suboptions. The names of these suboptions are usually strings rather than symbols.
| In[4]:= |
| Out[4]= |  |
Mathematica allows you to embed cells inside pieces of text. The option CellBaseline determines how such "inline cells" will be aligned vertically with respect to the text around them. In direct analogy with the option BaselinePosition for a Grid, the option CellBaseline specifies what aspect of the cell should be considered its baseline.
option | typical default value | |
| CellLabel | "" | a label for a cell |
| ShowCellLabel | True | whether to show the label for a cell |
| CellLabelAutoDelete | True | whether to delete the label if the cell is modified |
| CellTags | {} | tags for a cell |
| ShowCellTags | False | whether to show tags for a cell |
| ConversionRules | {} | rules for external conversions |
Options for ancillary data associated with cells.
In addition to the actual contents of a cell, it is often useful to associate various kinds of ancillary data with cells.
In a standard Mathematica session, cells containing successive lines of kernel input and output are given labels of the form In[n]:= and Out[n]=. The option ShowCellLabel determines whether such labels should be displayed. CellLabelAutoDelete determines whether the label on a cell should be removed if the contents of the cell are modified. Doing this ensures that In[n]:= and Out[n]= labels are only associated with unmodified pieces of kernel input and output.
Cell tags are typically used to associate keywords or other attributes with cells, which can be searched for using functions like NotebookFind. Destinations for hyperlinks in Mathematica notebooks are usually implemented using cell tags.
The option ConversionRules allows you to give a list containing entries such as "TeX"->data which specify how the contents of a cell should be converted to external formats. This is particularly relevant if you want to keep a copy of the original form of a cell that has been converted in Mathematica notebook format from some external format.
option | typical default value | |
| Deletable | True | whether to allow a cell to be deleted interactively with the front end |
| Copyable | True | whether to allow a cell to be copied |
| Selectable | True | whether to allow the contents of a cell to be selected |
| Editable | True | whether to allow the contents of a cell to be edited |
| Deployed | False | whether the user interface in the cell is active |
Options for controlling interactive operations on cells.
The options Deletable, Copyable, Selectable, and Editable allow you to control what interactive operations should be allowed on cells. By setting these options to False at the notebook level, you can protect all the cells in a notebook.
Deployed allows you to treat the contents of a cell as if they were a user interface. In a user interface, labels are typically not selectable and controls such as buttons can be used, but not modified. Deployed can also be set on specific elements inside a cell so that, for example, the output of Manipulate is always deployed even if the cell it is in has the Deployed option set to False.
option | typical default value | |
| Evaluator | "Local" | the name of the kernel to use for evaluations |
| Evaluatable | False | whether to allow the contents of a cell to be evaluated |
| CellAutoOverwrite | False | whether to overwrite previous output when new output is generated |
| GeneratedCell | False | whether this cell was generated from the kernel |
| InitializationCell | False | whether this cell should automatically be evaluated when the notebook is opened |
Mathematica makes it possible to specify a different evaluator for each cell in a notebook. But most often, the Evaluator option is set only at the notebook or global level, typically using the Kernel Configuration Options menu item in the front end.
The option CellAutoOverwrite is typically set to True for styles that represent Mathematica output. Doing this means that when you reevaluate a particular piece of input, Mathematica will automatically delete the output that was previously generated from that input, and will overwrite it with new output.
The option GeneratedCell is set whenever a cell is generated by an external request to the front end rather than by an interactive operation within the front end. Thus, for example, any cell obtained as an output or side effect from a kernel evaluation will have GeneratedCell->True. Cells generated by low-level functions designed to manipulate notebooks directly, such as NotebookWrite and NotebookApply, do not have the GeneratedCell option set.
option | typical default value | |
| PageBreakAbove | Automatic | whether to put a page break just above a particular cell |
| PageBreakWithin | Automatic | whether to allow a page break within a particular cell |
| PageBreakBelow | Automatic | whether to put a page break just below a particular cell |
| GroupPageBreakWithin | Automatic | whether to allow a page break within a particular group of cells |
Options for controlling page breaks when cells are printed.
When you display a notebook on the screen, you can scroll continuously through it. But if you print the notebook out, you have to decide where page breaks will occur. A setting of Automatic for a page break option tells Mathematica to make a page break if necessary; True specifies that a page break should always be made, while False specifies that it should never be.
Page breaks set using the PageBreakAbove and PageBreakBelow options also determine the breaks between slides in a slide show. When creating a slide show, you will typically use a cell with a special named style to determine where each slide begins. This named style will have one of the page-breaking options set on it.
