|  | ## Write Special Format

#### Synopsis

Writes attributes in a special user defined format.

#### Description

Using the parameter 'special_format', the user can specify the exact format. The $ sign has a special meaning and introduces a command (the following character) Additional arguments to this command may be supplied enclosing it in square brackets.

$a
  All attributes separated by the default separator
$a[separator]
  All attributes separated by separator
$s[separator][indexSeparator]
  Sparse format. For all non zero attributes the following strings are concatenated: the column index, the value of indexSeparator, the attribute value. Attributes are separated by separator.
$v[name]
  The value of the attribute with the given name (both regular and special attributes)
$k[index]
  The value of the attribute with the given index
$l
  The label
$p
  The predicted label
$d
  All prediction confidences for all classes in the form conf(class)=value
$d[class]
  The prediction confidence for the defined class as a simple number
$i
  The id
$w
  The weight
$b
  The batch number
$n
  The newline character
$t
  The tabulator character
$$
  The dollar sign
$[
  The '[' character
$]
  The ']' character

Make sure the format string ends with $n if you want examples to be separated by newlines.

#### Input

- input: expects: ExampleSet

#### Output

- through:

#### Parameters

- example set file: File to save the example set to.
- special format: Format string to use for output.
- fraction digits: The number of fraction digits in the output file (-1: all possible digits).
- quote nominal values: Indicates if nominal values should be quoted with double quotes.
- zipped: Indicates if the data file content should be zipped.
- overwrite mode: Indicates if an existing table should be overwritten or if data should be appended.
- encoding: The encoding used for reading or writing files.

#### ExampleProcess