Differences between revisions 5 and 12 (spanning 7 versions)

SPSS Data Types

SPSS exposes numeric and string data types.

Certain specialized forms of data are handled by formats that impact visualization and export, not storage. The primary example of this is date and time data.

Contents

SPSS Data Types
1. Numeric Data
  1. Date and Time Formats
2. String Data

Numeric Data

Numeric data is stored as double-precision floating point.

Data formats adjust the visualized/exported representation of a data point, often only truncating the value. Adjusting these data formats does not destroy precision.

Given the literal value 123.45...

General Format	Format	Representation
Fw	F8	123
Fw.d	F8.1	123.4
Nw	N8	00000123
Nw.d	N8.1	000123.4

Date and Time Formats

Format	Representation
DATETIME20	`dd-MMM-yyyy hh:mm:ss`
DATETIME17	`dd-MMM-yyyy hh:mm`
DATE11	`dd-MMM-yyyy`
DATE9	`dd-MMM-yy`
TIME8	`hh:mm:ss`
TIME5	`hh:mm`
ADATE10	`mm/dd/yyyy`

Note that MMM appears as JAN, not 001.

String Data

String data is stored at a fixed length. This length is defined and adjusted through the format; Aw where w is the width.

CategoryRicottone

-  ⇤ ← Revision 5 as of 2020-03-02 14:38:22 → 
  Size: 2654
  Editor: DominicRicottone
  Comment:
+   ← Revision 12 as of 2022-08-11 16:22:08 → ⇥
  Size: 1522
  Editor: DominicRicottone
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
-= SPSS Formats =
SPSS supports numeric variables and strings, with conversion options and some automatic conversion functionality. There are several formats on top of numerics that impact visualization, not storage.
+= SPSS Data Types =

SPSS exposes numeric and string data types.

Certain specialized forms of data are handled by formats that impact visualization and export, not storage. The primary example of this is date and time data.
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+== Numeric Data ==
-Line 10:
+Line 14:
-== Datetime ==
+Numeric data is stored as double-precision floating point.
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+Line 16:
-=== A warning about data input ===
+Data formats adjust the visualized/exported representation of a data point, often only truncating the value. Adjusting these data formats does not destroy precision.
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+Line 18:
-SPSS tries to be clever about reading data.
+Given the literal value 123.45...
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+Line 20:
-Under the format `TIME`, all of these are read in as `"01:02"`, even though the format is a minimum of 5-wide:
 * `"1:2"`
 * `"01 2"`
 * `"01:02"`

Under the format `DATE`, all of these are read in as `"28-OCT-90"`:
 * `"28-OCT-90"`
 * `"28/10/1990"`
 * `"28.OCT.90"`
 * `"28 October, 1990"`
+||'''General Format''' ||'''Format'''   ||'''Representation''' ||
||Fw                   ||F8             ||123                  ||
||Fw.d                 ||F8.1           ||123.4                ||
||Nw                   ||N8             ||00000123             ||
||Nw.d                 ||N8.1           ||000123.4             ||
-Line 29:
+Line 28:
-=== Datetime formats ===
+=== Date and Time Formats ===
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+Line 30:
-||'''Format''' ||'''Appears as...'''    ||'''Note'''              ||
||DATETIME20   ||`dd-MMM-yyyy hh:mm:ss` ||`MMM` is as JAN, not 001||
||DATETIME18   ||`dd-MMM-yyyy hh:mm`    ||`MMM` is as JAN, not 001||
||DATE11       ||`dd-MMM-yyyy`          ||`MMM` is as JAN, not 001||
||DATE7        ||`dd-MMM-yy`            ||`MMM` is as JAN, not 001||
||TIME8        ||`hh:mm:ss`             ||                        ||
||TIME5        ||`hh:mm`                ||                        ||
||ADATE10      ||`mm/dd/yyyy`           ||                        ||
||ADATE8       ||`mm/dd/yy`             ||                        ||
||EDATE10      ||`dd.mm.yyyy`           ||                        ||
||EDATE8       ||`dd.mm.yy`             ||                        ||
+||'''Format''' ||'''Representation'''   ||
||DATETIME20   ||`dd-MMM-yyyy hh:mm:ss` ||
||DATETIME17   ||`dd-MMM-yyyy hh:mm`    ||
||DATE11       ||`dd-MMM-yyyy`          ||
||DATE9        ||`dd-MMM-yy`            ||
||TIME8        ||`hh:mm:ss`             ||
||TIME5        ||`hh:mm`                ||
||ADATE10      ||`mm/dd/yyyy`           ||
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+Line 39:
-=== Parse Timestamps ===

A macro for timestamp conversion, from `dd/mm/yyyy hh:mm` to SPSS `DATETIME20`:

{{{
define !str2datetime (in=!tokens(1) / out=!cmdend)
  numeric !out (DATETIME20).
  compute !out =
   date.mdy(
    number(char.substr(!in,1,2), f2),
    number(char.substr(!in,4,2), f2),
    number(char.substr(!in,7,4), f4)
   )
   + time.hms(
    number(char.substr(!in,12,2), f2),
    number(char.substr(!in,15,2), f2),
    0
   )
  .
!enddefine.

!str2datetime in=mytimestampvar out=mydatetimevar.
}}}
+Note that `MMM` appears as `JAN`, not `001`.
-Line 74:
+Line 45:
-== Numerics ==
+== String Data ==
-Line 76:
+Line 47:
-Formats only truncate the displayed value, or the value translated into data files. SPSS always retains data to original precision.

Given 123.45...

||'''Format''' ||'''Using...''' ||'''Appears as...''' ||
||Fw           ||F8             ||123                 ||
||Fw.d         ||F8.1           ||123.4               ||
||Nw           ||N8             ||00000123            ||
||Nw.d         ||N8.1           ||000123.4            ||

----



== Strings ==

String variables are only formatted to a length. The format is specified as `AN` where `N` is the width.
+String data is stored at a fixed length. This length is defined and adjusted through the format; `Aw` where `w` is the width.

Diff for "SPSS/DataTypes"

SPSS Data Types

Numeric Data

Date and Time Formats

String Data