Mathematica Import/Export Format

Table (.dat)

Generic tabular data.
Stores numerical and textual information, formatted as a table.
Supports user-defined field and record separators, field delimiters, currency tokens, and number formats.
Plain text format.

Import and Export fully support the Table format and provide various data conversion and formatting options.

Import automatically recognizes common number formats, including C and Fortran notations.

Numbers without decimal points are imported as integers.

IMPORT AND EXPORT

Import["file.dat"] imports a Table file, returning a list of lists.

Export["file.dat", expr] exports a two-dimensional array or a Grid to a Table file.

Import["file.dat"] returns a two-dimensional array of strings and numbers, representing the rows and columns stored in the file.

Export["file.dat", array] formats array as rows and columns using the CForm of each element.

Mathematica automatically transforms arbitrary expressions to a list of lists when exporting to the Table format.

Import["file.dat", elem] imports the specified element from a Table file.

Import["file.dat", {elem, sub_a, sub_b, ...}] imports a subelement.

Import["file.dat", {{elem₁, elem₂, ...}}] imports multiple elements.

The import format can be specified with Import["file", "Table"] or Import["file", {"Table", elem, ...}].

Export["file.dat", expr, elem] creates a Table file by treating expr as specifying element elem.

Export["file.dat", {expr₁, expr₂, ...}, {{elem₁, elem₂, ...}}] treats each expr_i as specifying the corresponding elem_i.

Export["file.dat", expr, opt₁->val₁, ...] exports expr with the specified option elements taken to have the specified values.

Export["file.dat", {elem₁->expr₁, elem₂->expr₂, ...}, "Rules"] uses rules to specify the elements to be exported.

See the reference pages for full general information on Import and Export.

ImportString and ExportString support the Table format.

NOTEBOOK INTERFACE

Save Selection As exports the selected part of a notebook as a Table file.

ELEMENTS

General Import elements:

	"Elements"	list of elements and options available in this file
	"Rules"	full list of rules for each element and option
	"Options"	list of rules for options, properties and settings

Data representation elements:

	"Data"	two-dimensional array, representing the rows and columns
	"Grid"	table data as a Grid object

Import and Export use the "Data" element by default.

OPTIONS

General Export options:

	Alignment	None	how data is aligned within table columns
	CharacterEncoding	"UTF8"	raw character encoding used in the file

Possible settings for Alignment are None, Left, Center, and Right.

General Import option:

CharacterEncoding

"ASCII"

raw character encoding used in the file

Import and Export option:

"TextDelimiters"

Automatic

string or list of strings used to delimit non-numeric fields

By default, Export delimits text fields containing the field separator with double-quote characters.

With an explicit setting of "TextDelimiters", Export always uses the specified string tokens to delimit text fields, effectively cycling through the list of delimiters.

With "TextDelimiters" -> {"<", ">"} , Export wraps text fields in angular brackets.

Double-quote characters delimiting text fields are not imported by default.

Import options:

"CurrencyTokens"	{{"$", "", "", ""}, {"c", "", "p", "F"}}	currency units to be skipped when importing numerical values
"DateStringFormat"	None	date format, given as a DateString specification
"FieldSeparators"	{" ","\t"}	string tokens taken to separate columns
"IgnoreEmptyLines"	False	whether to ignore empty lines
"LineSeparators"	{"\r\n","\n","\r"}	string tokens taken to separate rows
"Numeric"	True	whether to import data fields as numbers if possible
"NumberPoint"	"."	decimal point string
"NumberSigns"	{"-","+"}	strings to use for signs of negative and positive numbers
"RepeatedSeparators"	True	whether to parse a sequence of field separators as a single separator
"HeaderLines"	0	number of lines to skip at the beginning of the file

Import converts table entries formatted as specified by the "DateStringFormat" option to a DateList representation of the form {y, m, d, h, m, s}.

Empty lines and lines containing only whitespace characters are converted to an empty list by default. With "IgnoreEmptyLines" set to True, Import will skip empty lines.

With "Numeric" -> False, numbers will be imported as strings in the form they appear in the file.

With the default setting for "LineSeparators", Import automatically recognizes all common conventions for the encoding of line-separator characters.

Export options:

	"FieldSeparators"	"\t"	string token used to separate columns
	"TableHeadings"	None	headings for table columns and rows

"TableHeadings" can be set to the following values:

	None	no labels
	Automatic	gives successive integer labels for columns and rows
	{"col₁","col₂",...}	list of column labels
	{rhead,chead}	specifies separate labels for the rows and columns