1 @c (modify-syntax-entry ?_ "w")
2 @c (modify-syntax-entry ?' "'")
3 @c (modify-syntax-entry ?@ "'")
6 @node Data Input and Output
7 @chapter Data Input and Output
14 Data are the focus of the @pspp{} language.
15 Each datum belongs to a @dfn{case} (also called an @dfn{observation}).
16 Each case represents an individual or ``experimental unit''.
17 For example, in the results of a survey, the names of the respondents,
18 their sex, age, etc.@: and their responses are all data and the data
19 pertaining to single respondent is a case.
21 the @pspp{} commands for defining variables and reading and writing data.
22 There are alternative commands to read data from predefined sources
23 such as system files or databases (@xref{GET, GET DATA}.)
26 These commands tell @pspp{} how to read data, but the data will not
27 actually be read until a procedure is executed.
31 * BEGIN DATA:: Embed data within a syntax file.
32 * CLOSE FILE HANDLE:: Close a file handle.
33 * DATAFILE ATTRIBUTE:: Set custom attributes on data files.
34 * DATASET:: Manage multiple datasets.
35 * DATA LIST:: Fundamental data reading command.
36 * END CASE:: Output the current case.
37 * END FILE:: Terminate the current input program.
38 * FILE HANDLE:: Support for special file formats.
39 * INPUT PROGRAM:: Support for complex input programs.
40 * LIST:: List cases in the active dataset.
41 * NEW FILE:: Clear the active dataset.
42 * PRINT:: Display values in print formats.
43 * PRINT EJECT:: Eject the current page then print.
44 * PRINT SPACE:: Print blank lines.
45 * REREAD:: Take another look at the previous input line.
46 * REPEATING DATA:: Multiple cases on a single line.
47 * WRITE:: Display values in write formats.
54 @cindex Embedding data in syntax files
55 @cindex Data, embedding in syntax files
63 @cmd{BEGIN DATA} and @cmd{END DATA} can be used to embed raw ASCII
64 data in a @pspp{} syntax file. @cmd{DATA LIST} or another input
65 procedure must be used before @cmd{BEGIN DATA} (@pxref{DATA LIST}).
66 @cmd{BEGIN DATA} and @cmd{END DATA} must be used together. @cmd{END
67 DATA} must appear by itself on a single line, with no leading
68 white space and exactly one space between the words @code{END} and
69 @code{DATA}, like this:
75 @node CLOSE FILE HANDLE
76 @section CLOSE FILE HANDLE
79 CLOSE FILE HANDLE @var{handle_name}.
82 @cmd{CLOSE FILE HANDLE} disassociates the name of a file handle with a
83 given file. The only specification is the name of the handle to close.
87 The file named INLINE, which represents data entered between @cmd{BEGIN
88 DATA} and @cmd{END DATA}, cannot be closed. Attempts to close it with
89 @cmd{CLOSE FILE HANDLE} have no effect.
91 @cmd{CLOSE FILE HANDLE} is a @pspp{} extension.
93 @node DATAFILE ATTRIBUTE
94 @section DATAFILE ATTRIBUTE
95 @vindex DATAFILE ATTRIBUTE
99 ATTRIBUTE=@var{name}('@var{value}') [@var{name}('@var{value}')]@dots{}
100 ATTRIBUTE=@var{name}@b{[}@var{index}@b{]}('@var{value}') [@var{name}@b{[}@var{index}@b{]}('@var{value}')]@dots{}
101 DELETE=@var{name} [@var{name}]@dots{}
102 DELETE=@var{name}@b{[}@var{index}@b{]} [@var{name}@b{[}@var{index}@b{]}]@dots{}
105 @cmd{DATAFILE ATTRIBUTE} adds, modifies, or removes user-defined
106 attributes associated with the active dataset. Custom data file
107 attributes are not interpreted by @pspp{}, but they are saved as part of
108 system files and may be used by other software that reads them.
110 Use the @subcmd{ATTRIBUTE} subcommand to add or modify a custom data file
111 attribute. Specify the name of the attribute as an identifier
112 (@pxref{Tokens}), followed by the desired value, in parentheses, as a
113 quoted string. Attribute names that begin with @code{$} are reserved
114 for @pspp{}'s internal use, and attribute names that begin with @code{@@}
115 or @code{$@@} are not displayed by most @pspp{} commands that display
116 other attributes. Other attribute names are not treated specially.
118 Attributes may also be organized into arrays. To assign to an array
119 element, add an integer array index enclosed in square brackets
120 (@code{[} and @code{]}) between the attribute name and value. Array
121 indexes start at 1, not 0. An attribute array that has a single
122 element (number 1) is not distinguished from a non-array attribute.
124 Use the @subcmd{DELETE} subcommand to delete an attribute. Specify an
125 attribute name by itself to delete an entire attribute, including all
126 array elements for attribute arrays. Specify an attribute name
127 followed by an array index in square brackets to delete a single
128 element of an attribute array. In the latter case, all the array
129 elements numbered higher than the deleted element are shifted down,
130 filling the vacated position.
132 To associate custom attributes with particular variables, instead of
133 with the entire active dataset, use @cmd{VARIABLE ATTRIBUTE}
134 (@pxref{VARIABLE ATTRIBUTE}) instead.
136 @cmd{DATAFILE ATTRIBUTE} takes effect immediately. It is not affected
137 by conditional and looping structures such as @cmd{DO IF} or
141 @section DATASET commands
145 DATASET NAME @var{name} [WINDOW=@{ASIS,FRONT@}].
146 DATASET ACTIVATE @var{name} [WINDOW=@{ASIS,FRONT@}].
147 DATASET COPY @var{name} [WINDOW=@{MINIMIZED,HIDDEN,FRONT@}].
148 DATASET DECLARE @var{name} [WINDOW=@{MINIMIZED,HIDDEN,FRONT@}].
149 DATASET CLOSE @{@var{name},*,ALL@}.
153 The @cmd{DATASET} commands simplify use of multiple datasets within a
154 @pspp{} session. They allow datasets to be created and destroyed. At
155 any given time, most @pspp{} commands work with a single dataset, called
159 The DATASET NAME command gives the active dataset the specified name, or
160 if it already had a name, it renames it. If another dataset already
161 had the given name, that dataset is deleted.
163 @vindex DATASET ACTIVATE
164 The DATASET ACTIVATE command selects the named dataset, which must
165 already exist, as the active dataset. Before switching the active
166 dataset, any pending transformations are executed, as if @cmd{EXECUTE}
167 had been specified. If the active dataset is unnamed before
168 switching, then it is deleted and becomes unavailable after switching.
171 The DATASET COPY command creates a new dataset with the specified
172 name, whose contents are a copy of the active dataset. Any pending
173 transformations are executed, as if @cmd{EXECUTE} had been specified,
174 before making the copy. If a dataset with the given name already
175 exists, it is replaced. If the name is the name of the active
176 dataset, then the active dataset becomes unnamed.
178 @vindex DATASET DECLARE
179 The DATASET DECLARE command creates a new dataset that is initially
180 ``empty,'' that is, it has no dictionary or data. If a dataset with
181 the given name already exists, this has no effect. The new dataset
182 can be used with commands that support output to a dataset,
183 e.g. AGGREGATE (@pxref{AGGREGATE}).
185 @vindex DATASET CLOSE
186 The DATASET CLOSE command deletes a dataset. If the active dataset is
187 specified by name, or if @samp{*} is specified, then the active
188 dataset becomes unnamed. If a different dataset is specified by name,
189 then it is deleted and becomes unavailable. Specifying ALL deletes
190 all datasets except for the active dataset, which becomes unnamed.
192 @vindex DATASET DISPLAY
193 The DATASET DISPLAY command lists all the currently defined datasets.
195 Many DATASET commands accept an optional @subcmd{WINDOW} subcommand. In the
196 @pspp{}IRE GUI, the value given for this subcommand influences how the
197 dataset's window is displayed. Outside the GUI, the @subcmd{WINDOW} subcommand
198 has no effect. The valid values are:
202 Do not change how the window is displayed. This is the default for
203 DATASET NAME and DATASET ACTIVATE.
206 Raise the dataset's window to the top. Make it the default dataset
210 Display the window ``minimized'' to an icon. Prefer other datasets
211 for running syntax. This is the default for DATASET COPY and DATASET
215 Hide the dataset's window. Prefer other datasets for running syntax.
221 @cindex reading data from a file
222 @cindex data, reading from a file
223 @cindex data, embedding in syntax files
224 @cindex embedding data in syntax files
226 Used to read text or binary data, @cmd{DATA LIST} is the most
227 fundamental data-reading command. Even the more sophisticated input
228 methods use @cmd{DATA LIST} commands as a building block.
229 Understanding @cmd{DATA LIST} is important to understanding how to use
230 @pspp{} to read your data files.
232 There are two major variants of @cmd{DATA LIST}, which are fixed
233 format and free format. In addition, free format has a minor variant,
234 list format, which is discussed in terms of its differences from vanilla
237 Each form of @cmd{DATA LIST} is described in detail below.
239 @xref{GET DATA}, for a command that offers a few enhancements over
240 DATA LIST and that may be substituted for DATA LIST in many
244 * DATA LIST FIXED:: Fixed columnar locations for data.
245 * DATA LIST FREE:: Any spacing you like.
246 * DATA LIST LIST:: Each case must be on a single line.
249 @node DATA LIST FIXED
250 @subsection DATA LIST FIXED
251 @vindex DATA LIST FIXED
252 @cindex reading fixed-format data
253 @cindex fixed-format data, reading
254 @cindex data, fixed-format, reading
255 @cindex embedding fixed-format data
260 [FILE='@var{file_name}' [ENCODING='@var{encoding}']]
261 [RECORDS=@var{record_count}]
263 [SKIP=@var{record_count}]
264 /[line_no] @var{var_spec}@dots{}
266 where each @var{var_spec} takes one of the forms
267 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
268 @var{var_list} (@var{fortran_spec})
271 @cmd{DATA LIST FIXED} is used to read data files that have values at fixed
272 positions on each line of single-line or multiline records. The
273 keyword FIXED is optional.
275 The @subcmd{FILE} subcommand must be used if input is to be taken from an
276 external file. It may be used to specify a file name as a string or a
277 file handle (@pxref{File Handles}). If the @subcmd{FILE} subcommand is not used,
278 then input is assumed to be specified within the command file using
279 @cmd{BEGIN DATA}@dots{}@cmd{END DATA} (@pxref{BEGIN DATA}).
280 The @subcmd{ENCODING} subcommand may only be used if the @subcmd{FILE} subcommand is also used.
281 It specifies the character encoding of the file.
283 The optional @subcmd{RECORDS} subcommand, which takes a single integer as an
284 argument, is used to specify the number of lines per record.
286 is not specified, then the number of lines per record is calculated from
287 the list of variable specifications later in @cmd{DATA LIST}.
289 The @subcmd{END} subcommand is only useful in conjunction with @cmd{INPUT
290 PROGRAM}. @xref{INPUT PROGRAM}, for details.
292 The optional @subcmd{SKIP} subcommand specifies a number of records to skip at
293 the beginning of an input file. It can be used to skip over a row
294 that contains variable names, for example.
296 @cmd{DATA LIST} can optionally output a table describing how the data file
297 will be read. The @subcmd{TABLE} subcommand enables this output, and
298 @subcmd{NOTABLE} disables it. The default is to output the table.
300 The list of variables to be read from the data list must come last.
301 Each line in the data record is introduced by a slash (@samp{/}).
302 Optionally, a line number may follow the slash. Following, any number
303 of variable specifications may be present.
305 Each variable specification consists of a list of variable names
306 followed by a description of their location on the input line. Sets of
307 variables may be specified using the @cmd{DATA LIST} @subcmd{TO} convention
309 Variables}). There are two ways to specify the location of the variable
310 on the line: columnar style and FORTRAN style.
312 In columnar style, the starting column and ending column for the field
313 are specified after the variable name, separated by a dash (@samp{-}).
314 For instance, the third through fifth columns on a line would be
315 specified @samp{3-5}. By default, variables are considered to be in
316 @samp{F} format (@pxref{Input and Output Formats}). (This default can be
317 changed; see @ref{SET} for more information.)
319 In columnar style, to use a variable format other than the default,
320 specify the format type in parentheses after the column numbers. For
321 instance, for alphanumeric @samp{A} format, use @samp{(A)}.
323 In addition, implied decimal places can be specified in parentheses
324 after the column numbers. As an example, suppose that a data file has a
325 field in which the characters @samp{1234} should be interpreted as
326 having the value 12.34. Then this field has two implied decimal places,
327 and the corresponding specification would be @samp{(2)}. If a field
328 that has implied decimal places contains a decimal point, then the
329 implied decimal places are not applied.
331 Changing the variable format and adding implied decimal places can be
332 done together; for instance, @samp{(N,5)}.
334 When using columnar style, the input and output width of each variable is
335 computed from the field width. The field width must be evenly divisible
336 into the number of variables specified.
338 FORTRAN style is an altogether different approach to specifying field
339 locations. With this approach, a list of variable input format
340 specifications, separated by commas, are placed after the variable names
341 inside parentheses. Each format specifier advances as many characters
342 into the input line as it uses.
344 Implied decimal places also exist in FORTRAN style. A format
345 specification with @var{d} decimal places also has @var{d} implied
348 In addition to the standard format specifiers (@pxref{Input and Output
349 Formats}), FORTRAN style defines some extensions:
353 Advance the current column on this line by one character position.
355 @item @code{T}@var{x}
356 Set the current column on this line to column @var{x}, with column
357 numbers considered to begin with 1 at the left margin.
359 @item @code{NEWREC}@var{x}
360 Skip forward @var{x} lines in the current record, resetting the active
361 column to the left margin.
364 Any format specifier may be preceded by a number. This causes the
365 action of that format specifier to be repeated the specified number of
368 @item (@var{spec1}, @dots{}, @var{specN})
369 Group the given specifiers together. This is most useful when preceded
370 by a repeat count. Groups may be nested arbitrarily.
373 FORTRAN and columnar styles may be freely intermixed. Columnar style
374 leaves the active column immediately after the ending column
375 specified. Record motion using @code{NEWREC} in FORTRAN style also
376 applies to later FORTRAN and columnar specifiers.
379 * DATA LIST FIXED Examples:: Examples of DATA LIST FIXED.
382 @node DATA LIST FIXED Examples
383 @unnumberedsubsubsec Examples
388 DATA LIST TABLE /NAME 1-10 (A) INFO1 TO INFO3 12-17 (1).
397 Defines the following variables:
401 @code{NAME}, a 10-character-wide string variable, in columns 1
405 @code{INFO1}, a numeric variable, in columns 12 through 13.
408 @code{INFO2}, a numeric variable, in columns 14 through 15.
411 @code{INFO3}, a numeric variable, in columns 16 through 17.
414 The @code{BEGIN DATA}/@code{END DATA} commands cause three cases to be
418 Case NAME INFO1 INFO2 INFO3
419 1 John Smith 10 23 11
420 2 Bob Arnold 12 20 15
424 The @code{TABLE} keyword causes @pspp{} to print out a table
425 describing the four variables defined.
429 DAT LIS FIL="survey.dat"
430 /ID 1-5 NAME 7-36 (A) SURNAME 38-67 (A) MINITIAL 69 (A)
435 Defines the following variables:
439 @code{ID}, a numeric variable, in columns 1-5 of the first record.
442 @code{NAME}, a 30-character string variable, in columns 7-36 of the
446 @code{SURNAME}, a 30-character string variable, in columns 38-67 of
450 @code{MINITIAL}, a 1-character string variable, in column 69 of
454 Fifty variables @code{Q01}, @code{Q02}, @code{Q03}, @dots{}, @code{Q49},
455 @code{Q50}, all numeric, @code{Q01} in column 7, @code{Q02} in column 8,
456 @dots{}, @code{Q49} in column 55, @code{Q50} in column 56, all in the second
460 Cases are separated by a blank record.
462 Data is read from file @file{survey.dat} in the current directory.
464 This example shows keywords abbreviated to their first 3 letters.
469 @subsection DATA LIST FREE
470 @vindex DATA LIST FREE
474 [(@{TAB,'@var{c}'@}, @dots{})]
476 [FILE='@var{file_name}' [ENCODING='@var{encoding}']]
477 [SKIP=@var{record_cnt}]
478 /@var{var_spec}@dots{}
480 where each @var{var_spec} takes one of the forms
481 @var{var_list} [(@var{type_spec})]
485 In free format, the input data is, by default, structured as a series
486 of fields separated by spaces, tabs, commas, or line breaks. Each
487 field's content may be unquoted, or it may be quoted with a pairs of
488 apostrophes (@samp{'}) or double quotes (@samp{"}). Unquoted white
489 space separates fields but is not part of any field. Any mix of
490 spaces, tabs, and line breaks is equivalent to a single space for the
491 purpose of separating fields, but consecutive commas will skip a
494 Alternatively, delimiters can be specified explicitly, as a
495 parenthesized, comma-separated list of single-character strings
496 immediately following FREE. The word TAB may also be used to specify
497 a tab character as a delimiter. When delimiters are specified
498 explicitly, only the given characters, plus line breaks, separate
499 fields. Furthermore, leading spaces at the beginnings of fields are
500 not trimmed, consecutive delimiters define empty fields, and no form
501 of quoting is allowed.
503 The @subcmd{NOTABLE} and @subcmd{TABLE} subcommands are as in @cmd{DATA LIST FIXED} above.
504 @subcmd{NOTABLE} is the default.
506 The @subcmd{FILE} and @subcmd{SKIP} subcommands are as in @cmd{DATA LIST FIXED} above.
508 The variables to be parsed are given as a single list of variable names.
509 This list must be introduced by a single slash (@samp{/}). The set of
510 variable names may contain format specifications in parentheses
511 (@pxref{Input and Output Formats}). Format specifications apply to all
512 variables back to the previous parenthesized format specification.
514 In addition, an asterisk may be used to indicate that all variables
515 preceding it are to have input/output format @samp{F8.0}.
517 Specified field widths are ignored on input, although all normal limits
518 on field width apply, but they are honored on output.
521 @subsection DATA LIST LIST
522 @vindex DATA LIST LIST
526 [(@{TAB,'@var{c}'@}, @dots{})]
528 [FILE='@var{file_name'} [ENCODING='@var{encoding}']]
529 [SKIP=@var{record_count}]
530 /@var{var_spec}@dots{}
532 where each @var{var_spec} takes one of the forms
533 @var{var_list} [(@var{type_spec})]
537 With one exception, @cmd{DATA LIST LIST} is syntactically and
538 semantically equivalent to @cmd{DATA LIST FREE}. The exception is
539 that each input line is expected to correspond to exactly one input
540 record. If more or fewer fields are found on an input line than
541 expected, an appropriate diagnostic is issued.
551 @cmd{END CASE} is used only within @cmd{INPUT PROGRAM} to output the
552 current case. @xref{INPUT PROGRAM}, for details.
562 @cmd{END FILE} is used only within @cmd{INPUT PROGRAM} to terminate
563 the current input program. @xref{INPUT PROGRAM}.
571 FILE HANDLE @var{handle_name}
572 /NAME='@var{file_name}
574 /TABWIDTH=@var{tab_width}
576 For binary files in native encoding with fixed-length records:
577 FILE HANDLE @var{handle_name}
578 /NAME='@var{file_name}'
580 [/LRECL=@var{rec_len}]
582 For binary files in native encoding with variable-length records:
583 FILE HANDLE @var{handle_name}
584 /NAME='@var{file_name}'
586 [/LRECL=@var{rec_len}]
588 For binary files encoded in EBCDIC:
589 FILE HANDLE @var{handle_name}
590 /NAME='@var{file_name}'
592 /RECFORM=@{FIXED,VARIABLE,SPANNED@}
593 [/LRECL=@var{rec_len}]
596 Use @cmd{FILE HANDLE} to associate a file handle name with a file and
597 its attributes, so that later commands can refer to the file by its
598 handle name. Names of text files can be specified directly on
599 commands that access files, so that @cmd{FILE HANDLE} is only needed when a
600 file is not an ordinary file containing lines of text. However,
601 @cmd{FILE HANDLE} may be used even for text files, and it may be
602 easier to specify a file's name once and later refer to it by an
605 Specify the file handle name as the identifier immediately following the
606 @cmd{FILE HANDLE} command name. The identifier INLINE is reserved for
607 representing data embedded in the syntax file (@pxref{BEGIN DATA}) The
608 file handle name must not already have been used in a previous
609 invocation of @cmd{FILE HANDLE}, unless it has been closed by an
610 intervening command (@pxref{CLOSE FILE HANDLE}).
612 The effect and syntax of @cmd{FILE HANDLE} depends on the selected MODE:
616 In CHARACTER mode, the default, the data file is read as a text file,
617 according to the local system's conventions, and each text line is
620 In CHARACTER mode only, tabs are expanded to spaces by input programs,
621 except by @cmd{DATA LIST FREE} with explicitly specified delimiters.
622 Each tab is 4 characters wide by default, but TABWIDTH (a @pspp{}
623 extension) may be used to specify an alternate width. Use a TABWIDTH
624 of 0 to suppress tab expansion.
627 In IMAGE mode, the data file is treated as a series of fixed-length
628 binary records. LRECL should be used to specify the record length in
629 bytes, with a default of 1024. On input, it is an error if an IMAGE
630 file's length is not a integer multiple of the record length. On
631 output, each record is padded with spaces or truncated, if necessary,
632 to make it exactly the correct length.
635 In BINARY mode, the data file is treated as a series of
636 variable-length binary records. LRECL may be specified, but its value
637 is ignored. The data for each record is both preceded and followed by
638 a 32-bit signed integer in little-endian byte order that specifies the
639 length of the record. (This redundancy permits records in these
640 files to be efficiently read in reverse order, although @pspp{} always
641 reads them in forward order.) The length does not include either
645 Mode 360 reads and writes files in formats first used for tapes in the
646 1960s on IBM mainframe operating systems and still supported today by
647 the modern successors of those operating systems. For more
648 information, see @cite{OS/400 Tape and Diskette Device Programming},
649 available on IBM's website.
651 Alphanumeric data in mode 360 files are encoded in EBCDIC. @pspp{}
652 translates EBCDIC to or from the host's native format as necessary on
653 input or output, using an ASCII/EBCDIC translation that is one-to-one,
654 so that a ``round trip'' from ASCII to EBCDIC back to ASCII, or vice
655 versa, always yields exactly the original data.
657 The @subcmd{RECFORM} subcommand is required in mode 360. The precise file
658 format depends on its setting:
663 This record format is equivalent to IMAGE mode, except for EBCDIC
666 IBM documentation calls this @code{*F} (fixed-length, deblocked)
671 The file comprises a sequence of zero or more variable-length blocks.
672 Each block begins with a 4-byte @dfn{block descriptor word} (BDW).
673 The first two bytes of the BDW are an unsigned integer in big-endian
674 byte order that specifies the length of the block, including the BDW
675 itself. The other two bytes of the BDW are ignored on input and
676 written as zeros on output.
678 Following the BDW, the remainder of each block is a sequence of one or
679 more variable-length records, each of which in turn begins with a
680 4-byte @dfn{record descriptor word} (RDW) that has the same format as
681 the BDW. Following the RDW, the remainder of each record is the
684 The maximum length of a record in VARIABLE mode is 65,527 bytes:
685 65,535 bytes (the maximum value of a 16-bit unsigned integer), minus 4
686 bytes for the BDW, minus 4 bytes for the RDW.
688 In mode VARIABLE, LRECL specifies a maximum, not a fixed, record
689 length, in bytes. The default is 8,192.
691 IBM documentation calls this @code{*VB} (variable-length, blocked,
696 The file format is like that of VARIABLE mode, except that logical
697 records may be split among multiple physical records (called
698 @dfn{segments}) or blocks. In SPANNED mode, the third byte of each
699 RDW is called the segment control character (SCC). Odd SCC values
700 cause the segment to be appended to a record buffer maintained in
701 memory; even values also append the segment and then flush its
702 contents to the input procedure. Canonically, SCC value 0 designates
703 a record not spanned among multiple segments, and values 1 through 3
704 designate the first segment, the last segment, or an intermediate
705 segment, respectively, within a multi-segment record. The record
706 buffer is also flushed at end of file regardless of the final record's
709 The maximum length of a logical record in VARIABLE mode is limited
710 only by memory available to @pspp{}. Segments are limited to 65,527
711 bytes, as in VARIABLE mode.
713 This format is similar to what IBM documentation call @code{*VS}
714 (variable-length, deblocked, spanned) format.
717 In mode 360, fields of type A that extend beyond the end of a record
718 read from disk are padded with spaces in the host's native character
719 set, which are then translated from EBCDIC to the native character
720 set. Thus, when the host's native character set is based on ASCII,
721 these fields are effectively padded with character @code{X'80'}. This
722 wart is implemented for compatibility.
725 The @subcmd{NAME} subcommand specifies the name of the file associated with the
726 handle. It is required in all modes but SCRATCH mode, in which its
730 @section INPUT PROGRAM
731 @vindex INPUT PROGRAM
735 @dots{} input commands @dots{}
739 @cmd{INPUT PROGRAM}@dots{}@cmd{END INPUT PROGRAM} specifies a
740 complex input program. By placing data input commands within @cmd{INPUT
741 PROGRAM}, @pspp{} programs can take advantage of more complex file
742 structures than available with only @cmd{DATA LIST}.
744 The first sort of extended input program is to simply put multiple @cmd{DATA
745 LIST} commands within the @cmd{INPUT PROGRAM}. This will cause all of
747 files to be read in parallel. Input will stop when end of file is
748 reached on any of the data files.
750 Transformations, such as conditional and looping constructs, can also be
751 included within @cmd{INPUT PROGRAM}. These can be used to combine input
752 from several data files in more complex ways. However, input will still
753 stop when end of file is reached on any of the data files.
755 To prevent @cmd{INPUT PROGRAM} from terminating at the first end of
757 the @subcmd{END} subcommand on @cmd{DATA LIST}. This subcommand takes a
759 which should be a numeric scratch variable (@pxref{Scratch Variables}).
760 (It need not be a scratch variable but otherwise the results can be
761 surprising.) The value of this variable is set to 0 when reading the
762 data file, or 1 when end of file is encountered.
764 Two additional commands are useful in conjunction with @cmd{INPUT PROGRAM}.
765 @cmd{END CASE} is the first. Normally each loop through the
767 structure produces one case. @cmd{END CASE} controls exactly
768 when cases are output. When @cmd{END CASE} is used, looping from the end of
769 @cmd{INPUT PROGRAM} to the beginning does not cause a case to be output.
771 @cmd{END FILE} is the second. When the @subcmd{END} subcommand is used on @cmd{DATA
772 LIST}, there is no way for the @cmd{INPUT PROGRAM} construct to stop
774 so an infinite loop results. @cmd{END FILE}, when executed,
775 stops the flow of input data and passes out of the @cmd{INPUT PROGRAM}
778 All this is very confusing. A few examples should help to clarify.
780 @c If you change this example, change the regression test1 in
781 @c tests/command/input-program.sh to match.
784 DATA LIST NOTABLE FILE='a.data'/X 1-10.
785 DATA LIST NOTABLE FILE='b.data'/Y 1-10.
790 The example above reads variable X from file @file{a.data} and variable
791 Y from file @file{b.data}. If one file is shorter than the other then
792 the extra data in the longer file is ignored.
794 @c If you change this example, change the regression test2 in
795 @c tests/command/input-program.sh to match.
801 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
804 DATA LIST NOTABLE END=#B FILE='b.data'/Y 1-10.
814 The above example reads variable X from @file{a.data} and variable Y from
815 @file{b.data}. If one file is shorter than the other then the missing
816 field is set to the system-missing value alongside the present value for
817 the remaining length of the longer file.
819 @c If you change this example, change the regression test3 in
820 @c tests/command/input-program.sh to match.
826 DATA LIST NOTABLE END=#B FILE='b.data'/X 1-10.
833 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
842 The above example reads data from file @file{a.data}, then from
843 @file{b.data}, and concatenates them into a single active dataset.
845 @c If you change this example, change the regression test4 in
846 @c tests/command/input-program.sh to match.
852 DATA LIST NOTABLE END=#EOF FILE='a.data'/X 1-10.
860 DATA LIST NOTABLE END=#EOF FILE='b.data'/X 1-10.
871 The above example does the same thing as the previous example, in a
874 @c If you change this example, make similar changes to the regression
875 @c test5 in tests/command/input-program.sh.
879 COMPUTE X=UNIFORM(10).
884 LIST/FORMAT=NUMBERED.
887 The above example causes an active dataset to be created consisting of 50
888 random variates between 0 and 10.
896 /VARIABLES=@var{var_list}
897 /CASES=FROM @var{start_index} TO @var{end_index} BY @var{incr_index}
898 /FORMAT=@{UNNUMBERED,NUMBERED@} @{WRAP,SINGLE@}
901 The @cmd{LIST} procedure prints the values of specified variables to the
904 The @subcmd{VARIABLES} subcommand specifies the variables whose values are to be
905 printed. Keyword VARIABLES is optional. If @subcmd{VARIABLES} subcommand is not
906 specified then all variables in the active dataset are printed.
908 The @subcmd{CASES} subcommand can be used to specify a subset of cases to be
909 printed. Specify @subcmd{FROM} and the case number of the first case to print,
910 @subcmd{TO} and the case number of the last case to print, and @subcmd{BY} and the number
911 of cases to advance between printing cases, or any subset of those
912 settings. If @subcmd{CASES} is not specified then all cases are printed.
914 The @subcmd{FORMAT} subcommand can be used to change the output format. @subcmd{NUMBERED}
915 will print case numbers along with each case; @subcmd{UNNUMBERED}, the default,
916 causes the case numbers to be omitted. The @subcmd{WRAP} and @subcmd{SINGLE} settings are
919 Case numbers start from 1. They are counted after all transformations
920 have been considered.
922 @cmd{LIST} attempts to fit all the values on a single line. If needed
923 to make them fit, variable names are displayed vertically. If values
924 cannot fit on a single line, then a multi-line format will be used.
926 @cmd{LIST} is a procedure. It causes the data to be read.
936 @cmd{NEW FILE} command clears the dictionary and data from the current
945 OUTFILE='@var{file_name}'
946 RECORDS=@var{n_lines}
948 [/[@var{line_no}] @var{arg}@dots{}]
950 @var{arg} takes one of the following forms:
951 '@var{string}' [@var{start}-@var{end}]
952 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
953 @var{var_list} (@var{fortran_spec})
957 The @cmd{PRINT} transformation writes variable data to the listing
958 file or an output file. @cmd{PRINT} is executed when a procedure
959 causes the data to be read. Follow @cmd{PRINT} by @cmd{EXECUTE} to
960 print variable data without invoking a procedure (@pxref{EXECUTE}).
962 All @cmd{PRINT} subcommands are optional. If no strings or variables
963 are specified, @cmd{PRINT} outputs a single blank line.
965 The @subcmd{OUTFILE} subcommand specifies the file to receive the output. The
966 file may be a file name as a string or a file handle (@pxref{File
967 Handles}). If @subcmd{OUTFILE} is not present then output will be sent to
968 @pspp{}'s output listing file. When @subcmd{OUTFILE} is present, a space is
969 inserted at beginning of each output line, even lines that otherwise
972 The @subcmd{RECORDS} subcommand specifies the number of lines to be output. The
973 number of lines may optionally be surrounded by parentheses.
975 @subcmd{TABLE} will cause the @cmd{PRINT} command to output a table to the listing file
976 that describes what it will print to the output file. @subcmd{NOTABLE}, the
977 default, suppresses this output table.
979 Introduce the strings and variables to be printed with a slash
980 (@samp{/}). Optionally, the slash may be followed by a number
981 indicating which output line will be specified. In the absence of this
982 line number, the next line number will be specified. Multiple lines may
983 be specified using multiple slashes with the intended output for a line
984 following its respective slash.
987 Literal strings may be printed. Specify the string itself. Optionally
988 the string may be followed by a column number or range of column
989 numbers, specifying the location on the line for the string to be
990 printed. Otherwise, the string will be printed at the current position
993 Variables to be printed can be specified in the same ways as available
994 for @cmd{DATA LIST FIXED} (@pxref{DATA LIST FIXED}). In addition, a
996 list may be followed by an asterisk (@samp{*}), which indicates that the
997 variables should be printed in their dictionary print formats, separated
998 by spaces. A variable list followed by a slash or the end of command
999 will be interpreted the same way.
1001 If a FORTRAN type specification is used to move backwards on the current
1002 line, then text is written at that point on the line, the line will be
1003 truncated to that length, although additional text being added will
1004 again extend the line to that length.
1007 @section PRINT EJECT
1012 OUTFILE='@var{file_name}'
1013 RECORDS=@var{n_lines}
1015 /[@var{line_no}] @var{arg}@dots{}
1017 @var{arg} takes one of the following forms:
1018 '@var{string}' [@var{start}-@var{end}]
1019 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
1020 @var{var_list} (@var{fortran_spec})
1024 @cmd{PRINT EJECT} advances to the beginning of a new output page in
1025 the listing file or output file. It can also output data in the same
1028 All @cmd{PRINT EJECT} subcommands are optional.
1030 Without @subcmd{OUTFILE}, @cmd{PRINT EJECT} ejects the current page in
1031 the listing file, then it produces other output, if any is specified.
1033 With @subcmd{OUTFILE}, @cmd{PRINT EJECT} writes its output to the specified file.
1034 The first line of output is written with @samp{1} inserted in the
1035 first column. Commonly, this is the only line of output. If
1036 additional lines of output are specified, these additional lines are
1037 written with a space inserted in the first column, as with @subcmd{PRINT}.
1039 @xref{PRINT}, for more information on syntax and usage.
1042 @section PRINT SPACE
1046 PRINT SPACE OUTFILE='file_name' n_lines.
1049 @cmd{PRINT SPACE} prints one or more blank lines to an output file.
1051 The @subcmd{OUTFILE} subcommand is optional. It may be used to direct output to
1052 a file specified by file name as a string or file handle (@pxref{File
1053 Handles}). If OUTFILE is not specified then output will be directed to
1056 n_lines is also optional. If present, it is an expression
1057 (@pxref{Expressions}) specifying the number of blank lines to be
1058 printed. The expression must evaluate to a nonnegative value.
1065 REREAD FILE=handle COLUMN=column.
1068 The @cmd{REREAD} transformation allows the previous input line in a
1070 already processed by @cmd{DATA LIST} or another input command to be re-read
1071 for further processing.
1073 The @subcmd{FILE} subcommand, which is optional, is used to specify the file to
1074 have its line re-read. The file must be specified as the name of a file
1075 handle (@pxref{File Handles}). If FILE is not specified then the last
1076 file specified on @cmd{DATA LIST} will be assumed (last file specified
1077 lexically, not in terms of flow-of-control).
1079 By default, the line re-read is re-read in its entirety. With the
1080 @subcmd{COLUMN} subcommand, a prefix of the line can be exempted from
1081 re-reading. Specify an expression (@pxref{Expressions}) evaluating to
1082 the first column that should be included in the re-read line. Columns
1083 are numbered from 1 at the left margin.
1085 Issuing @code{REREAD} multiple times will not back up in the data
1086 file. Instead, it will re-read the same line multiple times.
1088 @node REPEATING DATA
1089 @section REPEATING DATA
1090 @vindex REPEATING DATA
1094 /STARTS=@var{start}-@var{end}
1095 /OCCURS=@var{n_occurs}
1096 /FILE='@var{file_name}'
1097 /LENGTH=@var{length}
1098 /CONTINUED[=@var{cont_start}-@var{cont_end}]
1099 /ID=@var{id_start}-@var{id_end}=@var{id_var}
1101 /DATA=@var{var_spec}@dots{}
1103 where each @var{var_spec} takes one of the forms
1104 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
1105 @var{var_list} (@var{fortran_spec})
1108 @cmd{REPEATING DATA} parses groups of data repeating in
1109 a uniform format, possibly with several groups on a single line. Each
1110 group of data corresponds with one case. @cmd{REPEATING DATA} may only be
1111 used within an @cmd{INPUT PROGRAM} structure (@pxref{INPUT PROGRAM}).
1112 When used with @cmd{DATA LIST}, it
1113 can be used to parse groups of cases that share a subset of variables
1114 but differ in their other data.
1116 The @subcmd{STARTS} subcommand is required. Specify a range of columns, using
1117 literal numbers or numeric variable names. This range specifies the
1118 columns on the first line that are used to contain groups of data. The
1119 ending column is optional. If it is not specified, then the record
1120 width of the input file is used. For the inline file (@pxref{BEGIN
1121 DATA}) this is 80 columns; for a file with fixed record widths it is the
1122 record width; for other files it is 1024 characters by default.
1124 The @subcmd{OCCURS} subcommand is required. It must be a number or the name of a
1125 numeric variable. Its value is the number of groups present in the
1128 The @subcmd{DATA} subcommand is required. It must be the last subcommand
1129 specified. It is used to specify the data present within each repeating
1130 group. Column numbers are specified relative to the beginning of a
1131 group at column 1. Data is specified in the same way as with @cmd{DATA LIST
1132 FIXED} (@pxref{DATA LIST FIXED}).
1134 All other subcommands are optional.
1136 FILE specifies the file to read, either a file name as a string or a
1137 file handle (@pxref{File Handles}). If FILE is not present then the
1138 default is the last file handle used on @cmd{DATA LIST} (lexically, not in
1139 terms of flow of control).
1141 By default @cmd{REPEATING DATA} will output a table describing how it will
1142 parse the input data. Specifying @subcmd{NOTABLE} will disable this behavior;
1143 specifying TABLE will explicitly enable it.
1145 The @subcmd{LENGTH} subcommand specifies the length in characters of each group.
1146 If it is not present then length is inferred from the @subcmd{DATA} subcommand.
1147 LENGTH can be a number or a variable name.
1149 Normally all the data groups are expected to be present on a single
1150 line. Use the @subcmd{CONTINUED} command to indicate that data can be continued
1151 onto additional lines. If data on continuation lines starts at the left
1152 margin and continues through the entire field width, no column
1153 specifications are necessary on @subcmd{CONTINUED}. Otherwise, specify the
1154 possible range of columns in the same way as on STARTS.
1156 When data groups are continued from line to line, it is easy
1157 for cases to get out of sync through careless hand editing. The
1158 @subcmd{ID} subcommand allows a case identifier to be present on each line of
1159 repeating data groups. @cmd{REPEATING DATA} will check for the same
1160 identifier on each line and report mismatches. Specify the range of
1161 columns that the identifier will occupy, followed by an equals sign
1162 (@samp{=}) and the identifier variable name. The variable must already
1163 have been declared with @cmd{NUMERIC} or another command.
1165 @cmd{REPEATING DATA} should be the last command given within an
1166 @cmd{INPUT PROGRAM}. It should not be enclosed within a @cmd{LOOP}
1167 structure (@pxref{LOOP}). Use @cmd{DATA LIST} before, not after,
1168 @cmd{REPEATING DATA}.
1176 OUTFILE='@var{file_name}'
1177 RECORDS=@var{n_lines}
1179 /[@var{line_no}] @var{arg}@dots{}
1181 @var{arg} takes one of the following forms:
1182 '@var{string}' [@var{start}-@var{end}]
1183 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
1184 @var{var_list} (@var{fortran_spec})
1188 @code{WRITE} writes text or binary data to an output file.
1190 @xref{PRINT}, for more information on syntax and usage. @cmd{PRINT}
1191 and @cmd{WRITE} differ in only a few ways:
1195 @cmd{WRITE} uses write formats by default, whereas @cmd{PRINT} uses
1199 @cmd{PRINT} inserts a space between variables unless a format is
1200 explicitly specified, but @cmd{WRITE} never inserts space between
1201 variables in output.
1204 @cmd{PRINT} inserts a space at the beginning of each line that it
1205 writes to an output file (and @cmd{PRINT EJECT} inserts @samp{1} at
1206 the beginning of each line that should begin a new page), but
1207 @cmd{WRITE} does not.
1210 @cmd{PRINT} outputs the system-missing value according to its
1211 specified output format, whereas @cmd{WRITE} outputs the
1212 system-missing value as a field filled with spaces. Binary formats