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| = 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 supports numeric and [[SPSSStrings|string]] data. There are several formats on top of numeric data that impact visualization, not storage. These include [[SPSSDatetimes|dates and times]]. <<TableOfContents>> ---- == Numeric Data == Numeric data is stored as double-precision floating point. Data formats adjust the printed/ exported representation of a data point, often only truncating the value. Adjusting these data formats does not destroy precision. Given 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 === See [[SPSSDatetimes|here]] for more details on date, time, and datetime data. ||'''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`. |
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| == Datetime == | == String Data == |
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| === A warning about data input === SPSS tries to be clever about reading data. 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"` === Datetime formats === ||'''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` || || === 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. }}} ---- == Numerics == 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. |
SPSS Data Types
SPSS supports numeric and string data. There are several formats on top of numeric data that impact visualization, not storage. These include dates and times.
Numeric Data
Numeric data is stored as double-precision floating point. Data formats adjust the printed/ exported representation of a data point, often only truncating the value. Adjusting these data formats does not destroy precision.
Given 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
See here for more details on date, time, and datetime data.
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.