Format pseudo-function


Format controls the formatting of the cells it applies to. .Format is mainly for internal use.





Arguments to pass to a formatting function, or a call to a formatting function.


A format number.


The Format pseudo-function changes the formatting of table cells, and it specifies that all values it applies to will be formatted together.

In the first form, the “call” to Format looks like a call to format, but without specifying the argument x. When tabular() formats the output it will construct x from the entries in the table governed by the Format() specification, and pass it to the standard format function along with the other arguments.

In the second form, the “call” to Format contains a call to a function to do the formatting. Again, an argument x will be added to the call, containing the values to be formatted.

In the first form, or if the explicit function is named format, any cells in the table with character values will not be formatted. This is done so that a column can have mixed numeric and character values, and the numerics are not converted to character before formatting.

The pseudo-function .Format is mainly intended for internal use. It takes a single integer argument, saying that data governed by this call uses the same formatting as the format specification indicated by the integer. In this way entries can be commonly formatted even when they are not contiguous. The integers are assigned sequentially as the format specification is parsed; users will likely need trial and error to find the right value in a complicated table with multiple formats.


This is a “pseudo-function”: it takes the form of a function call, but is never actually called: it is handled specially by tabular.


# Using the first form
tabular( (Sepal.Length+Sepal.Width) ~ 
         Format(digits=2)*(mean + sd), data=iris )
# The same table, using the second form
tabular( (Sepal.Length+Sepal.Width) ~ 
         Format(format(digits=2))*(mean + sd), data=iris )
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