@chapter Combining Data Files
This chapter describes commands that allow data from system files,
-portable file, scratch files, and the active file to be combined to
-form a new active file. These commands can combine data files in the
+portable files, and open datasets to be combined to
+form a new active dataset. These commands can combine data files in the
following ways:
@itemize
@display
Per input file:
- /FILE=@{*,'file-name'@}
- [/RENAME=(src_names=target_names)@dots{}]
- [/IN=var_name]
+ /FILE=@{*,'@var{file_name}'@}
+ [/RENAME=(@var{src_names}=@var{target_names})@dots{}]
+ [/IN=@var{var_name}]
[/SORT]
Once per command:
- /BY var_list[(@{D|A@})] [var_list[(@{D|A@}]]@dots{}
- [/DROP=var_list]
- [/KEEP=var_list]
- [/FIRST=var_name]
- [/LAST=var_name]
+ /BY @var{var_list}[(@{D|A@})] [@var{var_list}[(@{D|A@}]]@dots{}
+ [/DROP=@var{var_list}]
+ [/KEEP=@var{var_list}]
+ [/FIRST=@var{var_name}]
+ [/LAST=@var{var_name}]
[/MAP]
@end display
following sections describe details specific to each command.
Each of these commands reads two or more input files and combines
-them. The command's output becomes the new active file. The input
+them. The command's output becomes the new active dataset. The input
files are not changed on disk.
The syntax of each command begins with a specification of the files to
-be read as input. For each input file, specify FILE with a system,
-portable, or scratch file's name as a string or a file handle
-(@pxref{File Handles}), or specify an asterisk (@samp{*}) to use the
-active file as input. Use of portable or scratch files on FILE is a
-PSPP extension.
+be read as input. For each input file, specify FILE with a system
+file or portable file's name as a string, a dataset (@pxref{Datasets})
+or file handle name, (@pxref{File Handles}), or an asterisk (@samp{*})
+to use the active dataset as input. Use of portable files on @subcmd{FILE} is a
+@pspp{} extension.
-At least two FILE subcommands must be specified. If the active file
+At least two @subcmd{FILE} subcommands must be specified. If the active dataset
is used as an input source, then @cmd{TEMPORARY} must not be in
effect.
-Each FILE subcommand may be followed by any number of RENAME
+Each @subcmd{FILE} subcommand may be followed by any number of @subcmd{RENAME}
subcommands that specify a parenthesized group or groups of variable
names as they appear in the input file, followed by those variables'
-new names, separated by an equals sign (@samp{=}),
-e.g. @samp{/RENAME=(OLD1=NEW1)(OLD2=NEW2)}. To rename a single
-variable, the parentheses may be omitted: @samp{/RENAME=OLD=NEW}.
+new names, separated by an equals sign (@subcmd{=}),
+e.g. @subcmd{/RENAME=(OLD1=NEW1)(OLD2=NEW2)}. To rename a single
+variable, the parentheses may be omitted: @subcmd{/RENAME=@var{old}=@var{new}}.
Within a parenthesized group, variables are renamed simultaneously, so
-that @samp{/RENAME=(A B=B A)} exchanges the names of variables A and
-B. Otherwise, renaming occurs in left-to-right order.
+that @subcmd{/RENAME=(@var{A} @var{B}=@var{B} @var{A})} exchanges the
+names of variables @var{A} and @var{B}.
+Otherwise, renaming occurs in left-to-right order.
-Each FILE subcommand may optionally be followed by a single IN
+Each @subcmd{FILE} subcommand may optionally be followed by a single @subcmd{IN}
subcommand, which creates a numeric variable with the specified name
and format F1.0. The IN variable takes value 1 in an output case if
the given input file contributed to that output case, and 0 otherwise.
-The DROP, KEEP, and RENAME subcommands have no effect on IN variables.
+The @subcmd{DROP}, @subcmd{KEEP}, and @subcmd{RENAME} subcommands have no effect on IN variables.
-If BY is used (see below), the SORT keyword must be specified after a
-FILE if that input file is not already sorted on the BY variables.
-When SORT is specified, PSPP sorts the input file's data on the BY
-variables before it applies it to the command. When SORT is used, BY
-is required. SORT is a PSPP extension.
+If @subcmd{BY} is used (see below), the @subcmd{SORT} keyword must be specified after a
+@subcmd{FILE} if that input file is not already sorted on the @subcmd{BY} variables.
+When @subcmd{SORT} is specified, @pspp{} sorts the input file's data on the @subcmd{BY}
+variables before it applies it to the command. When @subcmd{SORT} is used, @subcmd{BY}
+is required. @subcmd{SORT} is a @pspp{} extension.
-PSPP merges the dictionaries of all of the input files to form the new
-active file dictionary, like so:
+@pspp{} merges the dictionaries of all of the input files to form the
+dictionary of the new active dataset, like so:
@itemize @bullet
@item
-The new active file's variables are the union of all the input files'
+The variables in the new active dataset are the union of all the input files'
variables, matched based on their name. When a single input file
contains a variable with a given name, the output file will contain
exactly that variable. When more than one input file contains a
variable with a given name, those variables must all have the same
type (numeric or string) and, for string variables, the same width.
-Variables are matched after renaming with the RENAME subcommand.
-Thus, RENAME can be used to resolve conflicts.
+Variables are matched after renaming with the @subcmd{RENAME} subcommand.
+Thus, @subcmd{RENAME} can be used to resolve conflicts.
@item
The variable label for each output variable is taken from the first
similarly for value labels and missing values.
@item
-The new active file's file label (@pxref{FILE LABEL}) is that of the
-first specified FILE that has a file label.
+The file label of the new active dataset (@pxref{FILE LABEL}) is that of the
+first specified @subcmd{FILE} that has a file label.
@item
-The new active file's documents (@pxref{DOCUMENT}) are the
+The documents in the new active dataset (@pxref{DOCUMENT}) are the
concatenation of all the input files' documents, in the order in which
-the FILE subcommands are specified.
+the @subcmd{FILE} subcommands are specified.
@item
If all of the input files are weighted on the same variable, then the
-new active file is weighted on that variable. Otherwise, the new
-active file is not weighted.
+new active dataset is weighted on that variable. Otherwise, the new
+active dataset is not weighted.
@end itemize
The remaining subcommands apply to the output file as a whole, rather
than to individual input files. They must be specified at the end of
-the command specification, following all of the FILE and related
-subcommands. The most important of these subcommands is BY, which
+the command specification, following all of the @subcmd{FILE} and related
+subcommands. The most important of these subcommands is @subcmd{BY}, which
specifies a set of one or more variables that may be used to find
corresponding cases in each of the input files. The variables
-specified on BY must be present in all of the input files.
-Furthermore, if any of the input files are not sorted on the BY
-variables, then SORT must be specified for those input files.
+specified on @subcmd{BY} must be present in all of the input files.
+Furthermore, if any of the input files are not sorted on the @subcmd{BY}
+variables, then @subcmd{SORT} must be specified for those input files.
-The variables listed on BY may include (A) or (D) annotations to
+The variables listed on @subcmd{BY} may include (A) or (D) annotations to
specify ascending or descending sort order. @xref{SORT CASES}, for
-more details on this notation. Adding (A) or (D) to the BY subcommand
-specification is a PSPP extension.
+more details on this notation. Adding (A) or (D) to the @subcmd{BY} subcommand
+specification is a @pspp{} extension.
-The DROP subcommand can be used to specify a list of variables to
-exclude from the output. By contrast, the KEEP subcommand can be used
+The @subcmd{DROP} subcommand can be used to specify a list of variables to
+exclude from the output. By contrast, the @subcmd{KEEP} subcommand can be used
to specify variables to include in the output; all variables not
-listed are dropped. DROP and KEEP are executed in left-to-right order
-and may be repeated any number of times. DROP and KEEP do not affect
-variables created by the IN, FIRST, and LAST subcommands, which are
-always included in the new active file, but they can be used to drop
-BY variables.
-
-The FIRST and LAST subcommands are optional. They may only be
-specified on @cmd{MATCH FILES} and @cmd{ADD FILES}, and only when BY
-is used. FIRST and LIST each adds a numeric variable to the new
-active file, with the name given as the subcommand's argument and F1.0
-print and write formats. The value of the FIRST variable is 1 in the
-first output case with a given set of values for the BY variables, and
-0 in other cases. Similarly, the LAST variable is 1 in the last case
-with a given of BY values, and 0 in other cases.
+listed are dropped. @subcmd{DROP} and @subcmd{KEEP} are executed in left-to-right order
+and may be repeated any number of times. @subcmd{DROP} and @subcmd{KEEP} do not affect
+variables created by the @subcmd{IN}, @subcmd{FIRST}, and @subcmd{LAST} subcommands, which are
+always included in the new active dataset, but they can be used to drop
+@subcmd{BY} variables.
+
+The @subcmd{FIRST} and @subcmd{LAST} subcommands are optional. They may only be
+specified on @cmd{MATCH FILES} and @cmd{ADD FILES}, and only when @subcmd{BY}
+is used. @subcmd{FIRST} and @subcmd{LIST} each adds a numeric variable to the new
+active dataset, with the name given as the subcommand's argument and F1.0
+print and write formats. The value of the @subcmd{FIRST} variable is 1 in the
+first output case with a given set of values for the @subcmd{BY} variables, and
+0 in other cases. Similarly, the @subcmd{LAST} variable is 1 in the last case
+with a given of @subcmd{BY} values, and 0 in other cases.
When any of these commands creates an output case, variables that are
only in files that are not present for the current case are set to the
ADD FILES
Per input file:
- /FILE=@{*,'file-name'@}
- [/RENAME=(src_names=target_names)@dots{}]
- [/IN=var_name]
+ /FILE=@{*,'@var{file_name}'@}
+ [/RENAME=(@var{src_names}=@var{target_names})@dots{}]
+ [/IN=@var{var_name}]
[/SORT]
Once per command:
- [/BY var_list[(@{D|A@})] [var_list[(@{D|A@})]@dots{}]]
- [/DROP=var_list]
- [/KEEP=var_list]
- [/FIRST=var_name]
- [/LAST=var_name]
+ [/BY @var{var_list}[(@{D|A@})] [@var{var_list}[(@{D|A@})]@dots{}]]
+ [/DROP=@var{var_list}]
+ [/KEEP=@var{var_list}]
+ [/FIRST=@var{var_name}]
+ [/LAST=@var{var_name}]
[/MAP]
@end display
@cmd{ADD FILES} adds cases from multiple input files. The output,
-which replaces the active file, consists all of the cases in all of
+which replaces the active dataset, consists all of the cases in all of
the input files.
-ADD FILES shares the bulk of its syntax with other PSPP commands for
+@subcmd{ADD FILES} shares the bulk of its syntax with other @pspp{} commands for
combining multiple data files. @xref{Combining Files Common Syntax},
above, for an explanation of this common syntax.
-When BY is not used, the output of ADD FILES consists of all the cases
+When @subcmd{BY} is not used, the output of @subcmd{ADD FILES} consists of all the cases
from the first input file specified, followed by all the cases from
-the second file specified, and so on. When BY is used, the output is
-additionally sorted on the BY variables.
+the second file specified, and so on. When @subcmd{BY} is used, the output is
+additionally sorted on the @subcmd{BY} variables.
-When ADD FILES creates an output case, variables that are not part of
+When @subcmd{ADD FILES} creates an output case, variables that are not part of
the input file from which the case was drawn are set to the
system-missing value for numeric variables or spaces for string
variables.
MATCH FILES
Per input file:
- /@{FILE,TABLE@}=@{*,'file-name'@}
- [/RENAME=(src_names=target_names)@dots{}]
- [/IN=var_name]
+ /@{FILE,TABLE@}=@{*,'@var{file_name}'@}
+ [/RENAME=(@var{src_names}=@var{target_names})@dots{}]
+ [/IN=@var{var_name}]
[/SORT]
Once per command:
- /BY var_list[(@{D|A@}] [var_list[(@{D|A@})]@dots{}]
- [/DROP=var_list]
- [/KEEP=var_list]
- [/FIRST=var_name]
- [/LAST=var_name]
+ /BY @var{var_list}[(@{D|A@}] [@var{var_list}[(@{D|A@})]@dots{}]
+ [/DROP=@var{var_list}]
+ [/KEEP=@var{var_list}]
+ [/FIRST=@var{var_name}]
+ [/LAST=@var{var_name}]
[/MAP]
@end display
@cmd{MATCH FILES} merges sets of corresponding cases in multiple
input files into single cases in the output, combining their data.
-MATCH FILES shares the bulk of its syntax with other PSPP commands for
+@cmd{MATCH FILES} shares the bulk of its syntax with other @pspp{} commands for
combining multiple data files. @xref{Combining Files Common Syntax},
above, for an explanation of this common syntax.
-How MATCH FILES matches up cases from the input files depends on
-whether BY is specified:
+How @cmd{MATCH FILES} matches up cases from the input files depends on
+whether @subcmd{BY} is specified:
@itemize @bullet
@item
-If BY is not used, MATCH FILES combines the first case from each input
+If @subcmd{BY} is not used, @cmd{MATCH FILES} combines the first case from each input
file to produce the first output case, then the second case from each
input file for the second output case, and so on. If some input files
have fewer cases than others, then the shorter files do not contribute
to cases output after their input has been exhausted.
@item
-If BY is used, MATCH FILES combines cases from each input file that
-have identical values for the BY variables.
+If @subcmd{BY} is used, @cmd{MATCH FILES} combines cases from each input file that
+have identical values for the @subcmd{BY} variables.
-When BY is used, TABLE subcommands may be used to introduce @dfn{table
-lookup file}. TABLE has same syntax as FILE, and the RENAME, IN, and
-SORT subcommands may follow a TABLE in the same way as a FILE.
-Regardless of the number of TABLEs, at least one FILE must specified.
+When @subcmd{BY} is used, @subcmd{TABLE} subcommands may be used to introduce @dfn{table
+lookup file}. @subcmd{TABLE} has same syntax as @subcmd{FILE}, and the @subcmd{RENAME}, @subcmd{IN}, and
+@subcmd{SORT} subcommands may follow a @subcmd{TABLE} in the same way as @subcmd{FILE}.
+Regardless of the number of @subcmd{TABLE}s, at least one @subcmd{FILE} must specified.
Table lookup files are treated in the same way as other input files
for most purposes and, in particular, table lookup files must be
-sorted on the BY variables or the SORT subcommand must be specified
-for that TABLE.
+sorted on the @subcmd{BY} variables or the @subcmd{SORT} subcommand must be specified
+for that @subcmd{TABLE}.
Cases in table lookup files are not consumed after they have been used
once. This means that data in table lookup files can correspond to
-any number of cases in FILE input files. Table lookup files are
+any number of cases in @subcmd{FILE} input files. Table lookup files are
analogous to lookup tables in traditional relational database systems.
If a table lookup file contains more than one case with a given set of
-BY variables, only the first case is used.
+@subcmd{BY} variables, only the first case is used.
@end itemize
-When MATCH FILES creates an output case, variables that are only in
+When @cmd{MATCH FILES} creates an output case, variables that are only in
files that are not present for the current case are set to the
system-missing value for numeric variables or spaces for string
variables.
UPDATE
Per input file:
- /FILE=@{*,'file-name'@}
- [/RENAME=(src_names=target_names)@dots{}]
- [/IN=var_name]
+ /FILE=@{*,'@var{file_name}'@}
+ [/RENAME=(@var{src_names}=@var{target_names})@dots{}]
+ [/IN=@var{var_name}]
[/SORT]
Once per command:
- /BY var_list[(@{D|A@})] [var_list[(@{D|A@})]]@dots{}
- [/DROP=var_list]
- [/KEEP=var_list]
+ /BY @var{var_list}[(@{D|A@})] [@var{var_list}[(@{D|A@})]]@dots{}
+ [/DROP=@var{var_list}]
+ [/KEEP=@var{var_list}]
[/MAP]
@end display
@cmd{UPDATE} updates a @dfn{master file} by applying modifications
from one or more @dfn{transaction files}.
-UPDATE shares the bulk of its syntax with other PSPP commands for
+@cmd{UPDATE} shares the bulk of its syntax with other @pspp{} commands for
combining multiple data files. @xref{Combining Files Common Syntax},
above, for an explanation of this common syntax.
-At least two FILE subcommands must be specified. The first FILE
+At least two @subcmd{FILE} subcommands must be specified. The first @subcmd{FILE}
subcommand names the master file, and the rest name transaction files.
Every input file must either be sorted on the variables named on the
-BY subcommand, or the SORT subcommand must be used just after the FILE
+@subcmd{BY} subcommand, or the @subcmd{SORT} subcommand must be used just after the @subcmd{FILE}
subcommand for that input file.
-UPDATE uses the variables specified on the BY subcommand, which is
+@cmd{UPDATE} uses the variables specified on the @subcmd{BY} subcommand, which is
required, to attempt to match each case in a transaction file with a
case in the master file:
When a match is found, then the values of the variables present in the
transaction file replace those variable's values in the new active
file. If there are matching cases in more than more transaction file,
-PSPP applies the replacements from the first transaction file, then
+@pspp{} applies the replacements from the first transaction file, then
from the second transaction file, and so on. Similarly, if a single
-transaction file has cases with duplicate BY values, then those are
+transaction file has cases with duplicate @subcmd{BY} values, then those are
applied in order to the master file.
When a variable in a transaction file has a missing value or a string
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