MATHEMATICA IMPORT/EXPORT FORMAT
Table (.dat)
- 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["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, suba, subb, ...}] 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
as specifying the corresponding 
.
- 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.
- exports the selected part of a notebook as a Table file.
- 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
element by default.
- General Export options:
-
- Possible settings for Alignment are None, Left, Center, and Right.
- General Import option:
-
- 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
, Export always uses the specified string tokens to delimit text fields, effectively cycling through the list of delimiters.
- With
, 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
option to a DateList representation of the form 
.
- Empty lines and lines containing only whitespace characters are converted to an empty list by default. With
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
, 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 |
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 |
- Export encodes line separator characters using the convention of the computer system on which Mathematica is being run.
Export an array of random numbers as a table:
| Out[1]= |  |
Export a table formatted as a grid:
| Out[2]= |  |
Import the generated file:
| Out[3]= |  |
Use ExportString to create a formatted version of an array:
| Out[4]= |  |
Import a tabular data file that uses vertical bars as field separators:
| Out[1]= |  |
Import converts dates to a Mathematica DateList specification if the date format is specified:
| Out[1]= |  |
Create a UTF-8 encoded text file that contains currency tokens:
| Out[1]= |  |
When importing this file, currency tokens are automatically skipped:
| Out[2]= |  |
Mathematica automatically converts expressions to a list of lists when exporting to the Table format:
| Out[1]= |  |
| Out[2]= |  |
New in 4 | Last modified in 9
