Differences between revisions 9 and 13 (spanning 4 versions)

Stata Data Formats

The Stata data file format encodes variable metadata including display formats. While these formats primarily affect visualization, they can also encode critical information about how a variable should be used.

Display Formats

A display format is set like:

generate double my_datetime = clock(some_string, "YMDhms")
format my_datetime %tc

Numeric Formats

For the most part, all numeric types operate the same way in Stata.

See Numeric Functions for operating on this type of data.

Each underlying numeric data format applies a different display format by default. They are:

Type	Format
double	`%10.0g`
float	`%9.0g`
long	`%12.0g`
int	`%8.0g`
byte	`%8.0g`

The available numeric formats are:

general format (g) indicating that the number of decimal places should be shifted to improve readability
fixed width format (f) indicating that a fixed number of decimal places should be shown
scientific format (e) indicating that scientific notation should be used

As an example:

Value	With format `%9.4g`	With format `%9.4f`	With format `%9.2e`
3.14159	3.142	3.14	3.14e+00
314.159	314.2	314.16	3.14e+02

A c can be appended to any numeric format to display commas.

Date and Datetime Formats

Dates and datetimes are numeric data with a standardized, encoded meaning. The display format is what indicates the intended encoding. For the most part, this type of data counts days or milliseconds from the Stata epoch: 01jan1960 00:00:00.000.

See Datetime Functions for operating on this type of data.

Specifically, the date and datetime formats are:

Format	Unit
`%tc`	milliseconds ignoring leap seconds
`%tC`	milliseconds with leap seconds
`%td`	days
`%tw`	weeks
`%tm`	months
`%tq`	quarters
`%th`	half-years
`%ty`	years

These formats can be further customized, for visualization purposes only, with specific components.

Component	Specification	Displays As
Century	`CC`	`01`-`99`
Century	`cc`	`1`-`99`
Year	`YY`	`01`-`99`
Year	`yy`	`1`-`99`
Day of year	`JJJ`	`001`-`366`
Day of year	`jjj`	`1`-`366`
Month	`Mon`	`Jan`-`Dec`
Month	`Month`	`January`-`December`
Month	`mon`	`jan`-`dec`
Month	`month`	`january`-`december`
Month	`NN`	`01`-`12`
Month	`nn`	`1`-`12`
Day	`DD`	`01`-`31`
Day	`dd`	`1`-`31`
Day of week	`DAYNAME`	`Sunday`-`Saturday` (aligned)
Day of week	`Dayname`	`Sunday`-`Saturday` (unaligned)
Day of week	`Day`	`Sun`-`Sat`
Day of week	`Da`	`Su`-`Sa`
Day of week	`day`	`sun`-`sat`
Day of week	`da`	`su`-`sa`
Half-year	`h`	`1` or `2`
Quarter	`q`	`1`-`4`
Week	`WW`	`01`-`52`
Week	`ww`	`1`-`52`
Hour	`HH`	`00`-`23`
Hour	`Hh`	`00`-`12`
Hour	`hH`	`0`-`23`
Hour	`hh`	`0`-`12`
Minute	`MM`	`00`-`59`
Minute	`mm`	`0`-`59`
Second	`SS`	`00`-`60` (due to leap second)
Second	`ss`	`0`-`60` (due to leap second)
Tenths	`.s`	`.0`-`.9`
Hundredths	`.ss`	`.00`-`.99`
Thousandths	`.sss`	`.000`-`.999`
AM/PM	`am`/`pm`	`am` or `pm`
AM/PM	`a.m.`/`p.m.`	`a.m.` or `p.m.`
AM/PM	`AM`/`PM`	`AM` or `PM`
AM/PM	`A.M.`/`P.M.`	`A.M.` or `P.M.`
Period	`.`	`.`
Comma	`,`	`,`
Colon	`:`	`:`
Hyphen	`-`	`-`
Space
Forward slash	`/`	`/`
Back slash	`\`	`\`
Literal character	`!c`	`c`

A plus sign (+) can optionally delimit components for human readability. It is ignored otherwise.

String Formats

Alignment is controlled by the presence or absence of a negative sign (-) ahead of the width. A string variable formatted as %-18s will be left-justified; with a format of %18s it would have been right-justified.

-  ⇤ ← Revision 9 as of 2023-06-07 18:28:18 → 
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+   ← Revision 13 as of 2025-03-05 02:10:25 → ⇥
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+Additions are marked like this.
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-Stata uses '''display formats''' to extend the [[Stata/DataTypes|type system]].
+The Stata data file format encodes variable metadata including '''display formats'''. While these formats primarily affect visualization, they can also encode critical information about how a variable should be used.

See also the underlying [[Stata/DataTypes|data types]].
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+A display format is set like:

{{{
generate double my_datetime = clock(some_string, "YMDhms")
format my_datetime %tc
}}}

----
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+Line 25:
-=== Numeric Data ===
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+Line 26:
-The ''default'' display format for each numeric data type is as follows:
+=== Numeric Formats ===

For the most part, all numeric types operate the same way in Stata.

See [[Stata/NumericFunctions|Numeric Functions]] for operating on this type of data.

Each underlying numeric data format applies a different display format by default. They are:
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-The ''available'' numeric formats are '''`e`''', '''`f`''', and '''`g`'''. The '''general format''' (`g`) indicates that the number of decimal places should be shifted to improve readability. The '''fixed width format''' (`f`) indicates that a fixed number of decimal places should be shown. The '''scientific format''' (`e`) indicates that scientific notation should be used.
+The available numeric formats are:

 * '''general format''' (`g`) indicating that the number of decimal places should be shifted to improve readability
 * '''fixed width format''' (`f`) indicating that a fixed number of decimal places should be shown
 * '''scientific format''' (`e`) indicating that scientific notation should be used

As an example:
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+Line 53:
-A `c` can be appended to any numeric format to indicate that commas should be shown.
+A `c` can be appended to any numeric format to display commas.

----
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+Line 59:
-=== Date and Datetime Data ===
+=== Date and Datetime Formats ===
-Line 38:
+Line 61:
-Dates and datetimes are numeric data with unit-specific display formats. These are:
+Dates and datetimes are numeric data with a standardized, encoded meaning. The display format is what indicates the intended encoding. For the most part, this type of data counts days or milliseconds from the Stata epoch: `01jan1960 00:00:00.000`.

See [[Stata/DatetimeFunctions|Datetime Functions]] for operating on this type of data.

Specifically, the date and datetime formats are:
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+Line 77:
+These formats can be further customized, for visualization purposes only, with specific components.

||'''Component'''  ||'''Specification'''||'''Displays As'''              ||
||Century          ||`CC`               ||`01`-`99`                      ||
||Century          ||`cc`               ||`1`-`99`                       ||
||Year             ||`YY`               ||`01`-`99`                      ||
||Year             ||`yy`               ||`1`-`99`                       ||
||Day of year      ||`JJJ`              ||`001`-`366`                    ||
||Day of year      ||`jjj`              ||`1`-`366`                      ||
||Month            ||`Mon`              ||`Jan`-`Dec`                    ||
||Month            ||`Month`            ||`January`-`December`           ||
||Month            ||`mon`              ||`jan`-`dec`                    ||
||Month            ||`month`            ||`january`-`december`           ||
||Month            ||`NN`               ||`01`-`12`                      ||
||Month            ||`nn`               ||`1`-`12`                       ||
||Day              ||`DD`               ||`01`-`31`                      ||
||Day              ||`dd`               ||`1`-`31`                       ||
||Day of week      ||`DAYNAME`          ||`Sunday`-`Saturday` (aligned)  ||
||Day of week      ||`Dayname`          ||`Sunday`-`Saturday` (unaligned)||
||Day of week      ||`Day`              ||`Sun`-`Sat`                    ||
||Day of week      ||`Da`               ||`Su`-`Sa`                      ||
||Day of week      ||`day`              ||`sun`-`sat`                    ||
||Day of week      ||`da`               ||`su`-`sa`                      ||
||Half-year        ||`h`                ||`1` or `2`                     ||
||Quarter          ||`q`                ||`1`-`4`                        ||
||Week             ||`WW`               ||`01`-`52`                      ||
||Week             ||`ww`               ||`1`-`52`                       ||
||Hour             ||`HH`               ||`00`-`23`                      ||
||Hour             ||`Hh`               ||`00`-`12`                      ||
||Hour             ||`hH`               ||`0`-`23`                       ||
||Hour             ||`hh`               ||`0`-`12`                       ||
||Minute           ||`MM`               ||`00`-`59`                      ||
||Minute           ||`mm`               ||`0`-`59`                       ||
||Second           ||`SS`               ||`00`-`60` (due to leap second) ||
||Second           ||`ss`               ||`0`-`60` (due to leap second)  ||
||Tenths           ||`.s`               ||`.0`-`.9`                      ||
||Hundredths       ||`.ss`              ||`.00`-`.99`                    ||
||Thousandths      ||`.sss`             ||`.000`-`.999`                  ||
||AM/PM            ||`am`/`pm`          ||`am` or `pm`                   ||
||AM/PM            ||`a.m.`/`p.m.`      ||`a.m.` or `p.m.`               ||
||AM/PM            ||`AM`/`PM`          ||`AM` or `PM`                   ||
||AM/PM            ||`A.M.`/`P.M.`      ||`A.M.` or `P.M.`               ||
||Period           ||`.`                ||`.`                            ||
||Comma            ||`,`                ||`,`                            ||
||Colon            ||`:`                ||`:`                            ||
||Hyphen           ||`-`                ||`-`                            ||
||Space            ||` `                ||` `                            ||
||Forward slash    ||`/`                ||`/`                            ||
||Back slash       ||`\`                ||`\`                            ||
||Literal character||`!c`               ||`c`                            ||

A plus sign (`+`) can optionally delimit components for human readability. It is ignored otherwise.

----
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+Line 133:
-=== String Data ===
+=== String Formats ===
-Line 60:
+Line 142:
-== List ==
+== See also ==
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+Line 144:
-The '''`list`''' command examines data to (re-)allocate text width. If the longest value for a string variable with format `%18s` is 12 characters long, then `list` will only allocate 12 columns for that variable. This behavior can be disabled using the '''`nocompress`''' option.

Note that the default behavior has an impact on performance, especially for large datasets. As such, there is a '''`fast`''' option which is simply an alias for `nocompress`.

To truncate string values specifically, use the '''`string`''' option.

{{{
list comment, string(10)
}}}



=== String Value Alignment ===

The `list` command automatically shifts between two output modes based on the width of the listed variables and the width of the screen.

In '''table format''', the `list` command right-justifies all string values.

In '''display format''', string values are aligned according to the display format. A string value would be left-justified if the variable had a format of `%-18s`.



=== Variable Names ===

The `list` command also abbreviates variable names (defaulting to 8 characters). To increase that character limit, use the '''`abbreviate`''' option.

{{{
list very_long_variable_name, abbreviate(50)
}}}



=== Value Labels ===

The `list` command also uses labels (as opposed to values) when available. To override this behavior, use the '''`nolabel`''' option.

Value labels are aligned in the same way as string values; based on the output mode and the display format. Just as a string value would be left-justified if the variable had a format of `%-18s`, a label would be justified if the variable had a format of `%-8g`.
+[[https://www.stata.com/manuals/ddatetime.pdf|Stata datetimes]]

Diff for "Stata/DataFormats"

Stata Data Formats

Display Formats

Numeric Formats

Date and Datetime Formats

String Formats

See also