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= Data Formats = | = Stata Data Formats = In the topic of data formats in Stata, the concept of '''display formats''' is of primary interest. Stata uses display formats to extend the [[Stata/DataTypes|type system]]. Several commands have internal ideas about data formats. |
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=== Numeric Data === The ''default'' display format for each numeric data type is as follows: ||'''Type'''||'''Format'''|| ||double ||`%10.0g` || ||float ||`%9.0g` || ||long ||`%12.0g` || ||int ||`%8.0g` || ||byte ||`%8.0g` || 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. ||'''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 indicate that commas should be shown. === Date and Datetime Data === Dates and datetimes are numeric data with unit-specific display formats. These 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 || === String Data === 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. |
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== list == | == List == |
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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) }}} 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) }}} |
The '''`list`''' command resizes and reformats output to try and maximize accessibility. This involves automated truncation and alignment overriding display formats. For information on formatting the output of `lists`, see [[Stata/List#Data_Formats|here]]. |
Stata Data Formats
In the topic of data formats in Stata, the concept of display formats is of primary interest. Stata uses display formats to extend the type system.
Several commands have internal ideas about data formats.
Display Formats
Numeric Data
The default display format for each numeric data type is as follows:
Type |
Format |
double |
%10.0g |
float |
%9.0g |
long |
%12.0g |
int |
%8.0g |
byte |
%8.0g |
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.
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 indicate that commas should be shown.
Date and Datetime Data
Dates and datetimes are numeric data with unit-specific display formats. These 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 |
String Data
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.
List
The list command resizes and reformats output to try and maximize accessibility. This involves automated truncation and alignment overriding display formats. For information on formatting the output of lists, see here.