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}
281 subcommand is also used. It specifies the character encoding of the
282 file. @xref{INSERT}, for information on supported encodings.
284 The optional @subcmd{RECORDS} subcommand, which takes a single integer as an
285 argument, is used to specify the number of lines per record.
287 is not specified, then the number of lines per record is calculated from
288 the list of variable specifications later in @cmd{DATA LIST}.
290 The @subcmd{END} subcommand is only useful in conjunction with @cmd{INPUT
291 PROGRAM}. @xref{INPUT PROGRAM}, for details.
293 The optional @subcmd{SKIP} subcommand specifies a number of records to skip at
294 the beginning of an input file. It can be used to skip over a row
295 that contains variable names, for example.
297 @cmd{DATA LIST} can optionally output a table describing how the data file
298 will be read. The @subcmd{TABLE} subcommand enables this output, and
299 @subcmd{NOTABLE} disables it. The default is to output the table.
301 The list of variables to be read from the data list must come last.
302 Each line in the data record is introduced by a slash (@samp{/}).
303 Optionally, a line number may follow the slash. Following, any number
304 of variable specifications may be present.
306 Each variable specification consists of a list of variable names
307 followed by a description of their location on the input line. Sets of
308 variables may be specified using the @cmd{DATA LIST} @subcmd{TO} convention
310 Variables}). There are two ways to specify the location of the variable
311 on the line: columnar style and FORTRAN style.
313 In columnar style, the starting column and ending column for the field
314 are specified after the variable name, separated by a dash (@samp{-}).
315 For instance, the third through fifth columns on a line would be
316 specified @samp{3-5}. By default, variables are considered to be in
317 @samp{F} format (@pxref{Input and Output Formats}). (This default can be
318 changed; see @ref{SET} for more information.)
320 In columnar style, to use a variable format other than the default,
321 specify the format type in parentheses after the column numbers. For
322 instance, for alphanumeric @samp{A} format, use @samp{(A)}.
324 In addition, implied decimal places can be specified in parentheses
325 after the column numbers. As an example, suppose that a data file has a
326 field in which the characters @samp{1234} should be interpreted as
327 having the value 12.34. Then this field has two implied decimal places,
328 and the corresponding specification would be @samp{(2)}. If a field
329 that has implied decimal places contains a decimal point, then the
330 implied decimal places are not applied.
332 Changing the variable format and adding implied decimal places can be
333 done together; for instance, @samp{(N,5)}.
335 When using columnar style, the input and output width of each variable is
336 computed from the field width. The field width must be evenly divisible
337 into the number of variables specified.
339 FORTRAN style is an altogether different approach to specifying field
340 locations. With this approach, a list of variable input format
341 specifications, separated by commas, are placed after the variable names
342 inside parentheses. Each format specifier advances as many characters
343 into the input line as it uses.
345 Implied decimal places also exist in FORTRAN style. A format
346 specification with @var{d} decimal places also has @var{d} implied
349 In addition to the standard format specifiers (@pxref{Input and Output
350 Formats}), FORTRAN style defines some extensions:
354 Advance the current column on this line by one character position.
356 @item @code{T}@var{x}
357 Set the current column on this line to column @var{x}, with column
358 numbers considered to begin with 1 at the left margin.
360 @item @code{NEWREC}@var{x}
361 Skip forward @var{x} lines in the current record, resetting the active
362 column to the left margin.
365 Any format specifier may be preceded by a number. This causes the
366 action of that format specifier to be repeated the specified number of
369 @item (@var{spec1}, @dots{}, @var{specN})
370 Group the given specifiers together. This is most useful when preceded
371 by a repeat count. Groups may be nested arbitrarily.
374 FORTRAN and columnar styles may be freely intermixed. Columnar style
375 leaves the active column immediately after the ending column
376 specified. Record motion using @code{NEWREC} in FORTRAN style also
377 applies to later FORTRAN and columnar specifiers.
380 * DATA LIST FIXED Examples:: Examples of DATA LIST FIXED.
383 @node DATA LIST FIXED Examples
384 @unnumberedsubsubsec Examples
389 DATA LIST TABLE /NAME 1-10 (A) INFO1 TO INFO3 12-17 (1).
398 Defines the following variables:
402 @code{NAME}, a 10-character-wide string variable, in columns 1
406 @code{INFO1}, a numeric variable, in columns 12 through 13.
409 @code{INFO2}, a numeric variable, in columns 14 through 15.
412 @code{INFO3}, a numeric variable, in columns 16 through 17.
415 The @code{BEGIN DATA}/@code{END DATA} commands cause three cases to be
419 Case NAME INFO1 INFO2 INFO3
420 1 John Smith 10 23 11
421 2 Bob Arnold 12 20 15
425 The @code{TABLE} keyword causes @pspp{} to print out a table
426 describing the four variables defined.
430 DAT LIS FIL="survey.dat"
431 /ID 1-5 NAME 7-36 (A) SURNAME 38-67 (A) MINITIAL 69 (A)
436 Defines the following variables:
440 @code{ID}, a numeric variable, in columns 1-5 of the first record.
443 @code{NAME}, a 30-character string variable, in columns 7-36 of the
447 @code{SURNAME}, a 30-character string variable, in columns 38-67 of
451 @code{MINITIAL}, a 1-character string variable, in column 69 of
455 Fifty variables @code{Q01}, @code{Q02}, @code{Q03}, @dots{}, @code{Q49},
456 @code{Q50}, all numeric, @code{Q01} in column 7, @code{Q02} in column 8,
457 @dots{}, @code{Q49} in column 55, @code{Q50} in column 56, all in the second
461 Cases are separated by a blank record.
463 Data is read from file @file{survey.dat} in the current directory.
465 This example shows keywords abbreviated to their first 3 letters.
470 @subsection DATA LIST FREE
471 @vindex DATA LIST FREE
475 [(@{TAB,'@var{c}'@}, @dots{})]
477 [FILE='@var{file_name}' [ENCODING='@var{encoding}']]
478 [SKIP=@var{record_cnt}]
479 /@var{var_spec}@dots{}
481 where each @var{var_spec} takes one of the forms
482 @var{var_list} [(@var{type_spec})]
486 In free format, the input data is, by default, structured as a series
487 of fields separated by spaces, tabs, commas, or line breaks. Each
488 field's content may be unquoted, or it may be quoted with a pairs of
489 apostrophes (@samp{'}) or double quotes (@samp{"}). Unquoted white
490 space separates fields but is not part of any field. Any mix of
491 spaces, tabs, and line breaks is equivalent to a single space for the
492 purpose of separating fields, but consecutive commas will skip a
495 Alternatively, delimiters can be specified explicitly, as a
496 parenthesized, comma-separated list of single-character strings
497 immediately following FREE. The word TAB may also be used to specify
498 a tab character as a delimiter. When delimiters are specified
499 explicitly, only the given characters, plus line breaks, separate
500 fields. Furthermore, leading spaces at the beginnings of fields are
501 not trimmed, consecutive delimiters define empty fields, and no form
502 of quoting is allowed.
504 The @subcmd{NOTABLE} and @subcmd{TABLE} subcommands are as in @cmd{DATA LIST FIXED} above.
505 @subcmd{NOTABLE} is the default.
507 The @subcmd{FILE}, @subcmd{SKIP}, and @subcmd{ENCODING} subcommands
508 are as in @cmd{DATA LIST FIXED} above.
510 The variables to be parsed are given as a single list of variable names.
511 This list must be introduced by a single slash (@samp{/}). The set of
512 variable names may contain format specifications in parentheses
513 (@pxref{Input and Output Formats}). Format specifications apply to all
514 variables back to the previous parenthesized format specification.
516 In addition, an asterisk may be used to indicate that all variables
517 preceding it are to have input/output format @samp{F8.0}.
519 Specified field widths are ignored on input, although all normal limits
520 on field width apply, but they are honored on output.
523 @subsection DATA LIST LIST
524 @vindex DATA LIST LIST
528 [(@{TAB,'@var{c}'@}, @dots{})]
530 [FILE='@var{file_name}' [ENCODING='@var{encoding}']]
531 [SKIP=@var{record_count}]
532 /@var{var_spec}@dots{}
534 where each @var{var_spec} takes one of the forms
535 @var{var_list} [(@var{type_spec})]
539 With one exception, @cmd{DATA LIST LIST} is syntactically and
540 semantically equivalent to @cmd{DATA LIST FREE}. The exception is
541 that each input line is expected to correspond to exactly one input
542 record. If more or fewer fields are found on an input line than
543 expected, an appropriate diagnostic is issued.
553 @cmd{END CASE} is used only within @cmd{INPUT PROGRAM} to output the
554 current case. @xref{INPUT PROGRAM}, for details.
564 @cmd{END FILE} is used only within @cmd{INPUT PROGRAM} to terminate
565 the current input program. @xref{INPUT PROGRAM}.
573 FILE HANDLE @var{handle_name}
574 /NAME='@var{file_name}
577 /TABWIDTH=@var{tab_width}
578 [ENCODING='@var{encoding}']
580 For binary files in native encoding with fixed-length records:
581 FILE HANDLE @var{handle_name}
582 /NAME='@var{file_name}'
584 [/LRECL=@var{rec_len}]
585 [ENCODING='@var{encoding}']
587 For binary files in native encoding with variable-length records:
588 FILE HANDLE @var{handle_name}
589 /NAME='@var{file_name}'
591 [/LRECL=@var{rec_len}]
592 [ENCODING='@var{encoding}']
594 For binary files encoded in EBCDIC:
595 FILE HANDLE @var{handle_name}
596 /NAME='@var{file_name}'
598 /RECFORM=@{FIXED,VARIABLE,SPANNED@}
599 [/LRECL=@var{rec_len}]
600 [ENCODING='@var{encoding}']
603 Use @cmd{FILE HANDLE} to associate a file handle name with a file and
604 its attributes, so that later commands can refer to the file by its
605 handle name. Names of text files can be specified directly on
606 commands that access files, so that @cmd{FILE HANDLE} is only needed when a
607 file is not an ordinary file containing lines of text. However,
608 @cmd{FILE HANDLE} may be used even for text files, and it may be
609 easier to specify a file's name once and later refer to it by an
612 Specify the file handle name as the identifier immediately following the
613 @cmd{FILE HANDLE} command name. The identifier INLINE is reserved for
614 representing data embedded in the syntax file (@pxref{BEGIN DATA}) The
615 file handle name must not already have been used in a previous
616 invocation of @cmd{FILE HANDLE}, unless it has been closed by an
617 intervening command (@pxref{CLOSE FILE HANDLE}).
619 The effect and syntax of @cmd{FILE HANDLE} depends on the selected MODE:
623 In CHARACTER mode, the default, the data file is read as a text file.
624 Each text line is read as one record.
626 In CHARACTER mode only, tabs are expanded to spaces by input programs,
627 except by @cmd{DATA LIST FREE} with explicitly specified delimiters.
628 Each tab is 4 characters wide by default, but TABWIDTH (a @pspp{}
629 extension) may be used to specify an alternate width. Use a TABWIDTH
630 of 0 to suppress tab expansion.
632 A file written in CHARACTER mode by default uses the line ends of the
633 system on which PSPP is running, that is, on Windows, the default is
634 CR LF line ends, and on other systems the default is LF only. Specify
635 ENDS as CR or CRLF to override the default. PSPP reads files using
636 either convention on any kind of system, regardless of ENDS.
639 In IMAGE mode, the data file is treated as a series of fixed-length
640 binary records. LRECL should be used to specify the record length in
641 bytes, with a default of 1024. On input, it is an error if an IMAGE
642 file's length is not a integer multiple of the record length. On
643 output, each record is padded with spaces or truncated, if necessary,
644 to make it exactly the correct length.
647 In BINARY mode, the data file is treated as a series of
648 variable-length binary records. LRECL may be specified, but its value
649 is ignored. The data for each record is both preceded and followed by
650 a 32-bit signed integer in little-endian byte order that specifies the
651 length of the record. (This redundancy permits records in these
652 files to be efficiently read in reverse order, although @pspp{} always
653 reads them in forward order.) The length does not include either
657 Mode 360 reads and writes files in formats first used for tapes in the
658 1960s on IBM mainframe operating systems and still supported today by
659 the modern successors of those operating systems. For more
660 information, see @cite{OS/400 Tape and Diskette Device Programming},
661 available on IBM's website.
663 Alphanumeric data in mode 360 files are encoded in EBCDIC. @pspp{}
664 translates EBCDIC to or from the host's native format as necessary on
665 input or output, using an ASCII/EBCDIC translation that is one-to-one,
666 so that a ``round trip'' from ASCII to EBCDIC back to ASCII, or vice
667 versa, always yields exactly the original data.
669 The @subcmd{RECFORM} subcommand is required in mode 360. The precise file
670 format depends on its setting:
675 This record format is equivalent to IMAGE mode, except for EBCDIC
678 IBM documentation calls this @code{*F} (fixed-length, deblocked)
683 The file comprises a sequence of zero or more variable-length blocks.
684 Each block begins with a 4-byte @dfn{block descriptor word} (BDW).
685 The first two bytes of the BDW are an unsigned integer in big-endian
686 byte order that specifies the length of the block, including the BDW
687 itself. The other two bytes of the BDW are ignored on input and
688 written as zeros on output.
690 Following the BDW, the remainder of each block is a sequence of one or
691 more variable-length records, each of which in turn begins with a
692 4-byte @dfn{record descriptor word} (RDW) that has the same format as
693 the BDW. Following the RDW, the remainder of each record is the
696 The maximum length of a record in VARIABLE mode is 65,527 bytes:
697 65,535 bytes (the maximum value of a 16-bit unsigned integer), minus 4
698 bytes for the BDW, minus 4 bytes for the RDW.
700 In mode VARIABLE, LRECL specifies a maximum, not a fixed, record
701 length, in bytes. The default is 8,192.
703 IBM documentation calls this @code{*VB} (variable-length, blocked,
708 The file format is like that of VARIABLE mode, except that logical
709 records may be split among multiple physical records (called
710 @dfn{segments}) or blocks. In SPANNED mode, the third byte of each
711 RDW is called the segment control character (SCC). Odd SCC values
712 cause the segment to be appended to a record buffer maintained in
713 memory; even values also append the segment and then flush its
714 contents to the input procedure. Canonically, SCC value 0 designates
715 a record not spanned among multiple segments, and values 1 through 3
716 designate the first segment, the last segment, or an intermediate
717 segment, respectively, within a multi-segment record. The record
718 buffer is also flushed at end of file regardless of the final record's
721 The maximum length of a logical record in VARIABLE mode is limited
722 only by memory available to @pspp{}. Segments are limited to 65,527
723 bytes, as in VARIABLE mode.
725 This format is similar to what IBM documentation call @code{*VS}
726 (variable-length, deblocked, spanned) format.
729 In mode 360, fields of type A that extend beyond the end of a record
730 read from disk are padded with spaces in the host's native character
731 set, which are then translated from EBCDIC to the native character
732 set. Thus, when the host's native character set is based on ASCII,
733 these fields are effectively padded with character @code{X'80'}. This
734 wart is implemented for compatibility.
737 The @subcmd{NAME} subcommand specifies the name of the file associated with the
738 handle. It is required in all modes but SCRATCH mode, in which its
741 The ENCODING subcommand specifies the encoding of text in the file.
742 For reading text files in CHARACTER mode, all of the forms described
743 for ENCODING on the INSERT command are supported (@pxref{INSERT}).
744 For reading in other file-based modes, encoding autodetection is not
745 supported; if the specified encoding requests autodetection then the
746 default encoding will be used. This is also true when a file handle
747 is used for writing a file in any mode.
750 @section INPUT PROGRAM
751 @vindex INPUT PROGRAM
755 @dots{} input commands @dots{}
759 @cmd{INPUT PROGRAM}@dots{}@cmd{END INPUT PROGRAM} specifies a
760 complex input program. By placing data input commands within @cmd{INPUT
761 PROGRAM}, @pspp{} programs can take advantage of more complex file
762 structures than available with only @cmd{DATA LIST}.
764 The first sort of extended input program is to simply put multiple @cmd{DATA
765 LIST} commands within the @cmd{INPUT PROGRAM}. This will cause all of
767 files to be read in parallel. Input will stop when end of file is
768 reached on any of the data files.
770 Transformations, such as conditional and looping constructs, can also be
771 included within @cmd{INPUT PROGRAM}. These can be used to combine input
772 from several data files in more complex ways. However, input will still
773 stop when end of file is reached on any of the data files.
775 To prevent @cmd{INPUT PROGRAM} from terminating at the first end of
777 the @subcmd{END} subcommand on @cmd{DATA LIST}. This subcommand takes a
779 which should be a numeric scratch variable (@pxref{Scratch Variables}).
780 (It need not be a scratch variable but otherwise the results can be
781 surprising.) The value of this variable is set to 0 when reading the
782 data file, or 1 when end of file is encountered.
784 Two additional commands are useful in conjunction with @cmd{INPUT PROGRAM}.
785 @cmd{END CASE} is the first. Normally each loop through the
787 structure produces one case. @cmd{END CASE} controls exactly
788 when cases are output. When @cmd{END CASE} is used, looping from the end of
789 @cmd{INPUT PROGRAM} to the beginning does not cause a case to be output.
791 @cmd{END FILE} is the second. When the @subcmd{END} subcommand is used on @cmd{DATA
792 LIST}, there is no way for the @cmd{INPUT PROGRAM} construct to stop
794 so an infinite loop results. @cmd{END FILE}, when executed,
795 stops the flow of input data and passes out of the @cmd{INPUT PROGRAM}
798 @cmd{INPUT PROGRAM} must contain at least one @cmd{DATA LIST} or
799 @cmd{END FILE} command.
801 All this is very confusing. A few examples should help to clarify.
803 @c If you change this example, change the regression test1 in
804 @c tests/command/input-program.sh to match.
807 DATA LIST NOTABLE FILE='a.data'/X 1-10.
808 DATA LIST NOTABLE FILE='b.data'/Y 1-10.
813 The example above reads variable X from file @file{a.data} and variable
814 Y from file @file{b.data}. If one file is shorter than the other then
815 the extra data in the longer file is ignored.
817 @c If you change this example, change the regression test2 in
818 @c tests/command/input-program.sh to match.
824 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
827 DATA LIST NOTABLE END=#B FILE='b.data'/Y 1-10.
837 The above example reads variable X from @file{a.data} and variable Y from
838 @file{b.data}. If one file is shorter than the other then the missing
839 field is set to the system-missing value alongside the present value for
840 the remaining length of the longer file.
842 @c If you change this example, change the regression test3 in
843 @c tests/command/input-program.sh to match.
849 DATA LIST NOTABLE END=#B FILE='b.data'/X 1-10.
856 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
865 The above example reads data from file @file{a.data}, then from
866 @file{b.data}, and concatenates them into a single active dataset.
868 @c If you change this example, change the regression test4 in
869 @c tests/command/input-program.sh to match.
875 DATA LIST NOTABLE END=#EOF FILE='a.data'/X 1-10.
883 DATA LIST NOTABLE END=#EOF FILE='b.data'/X 1-10.
894 The above example does the same thing as the previous example, in a
897 @c If you change this example, make similar changes to the regression
898 @c test5 in tests/command/input-program.sh.
902 COMPUTE X=UNIFORM(10).
907 LIST/FORMAT=NUMBERED.
910 The above example causes an active dataset to be created consisting of 50
911 random variates between 0 and 10.
919 /VARIABLES=@var{var_list}
920 /CASES=FROM @var{start_index} TO @var{end_index} BY @var{incr_index}
921 /FORMAT=@{UNNUMBERED,NUMBERED@} @{WRAP,SINGLE@}
924 The @cmd{LIST} procedure prints the values of specified variables to the
927 The @subcmd{VARIABLES} subcommand specifies the variables whose values are to be
928 printed. Keyword VARIABLES is optional. If @subcmd{VARIABLES} subcommand is not
929 specified then all variables in the active dataset are printed.
931 The @subcmd{CASES} subcommand can be used to specify a subset of cases to be
932 printed. Specify @subcmd{FROM} and the case number of the first case to print,
933 @subcmd{TO} and the case number of the last case to print, and @subcmd{BY} and the number
934 of cases to advance between printing cases, or any subset of those
935 settings. If @subcmd{CASES} is not specified then all cases are printed.
937 The @subcmd{FORMAT} subcommand can be used to change the output format. @subcmd{NUMBERED}
938 will print case numbers along with each case; @subcmd{UNNUMBERED}, the default,
939 causes the case numbers to be omitted. The @subcmd{WRAP} and @subcmd{SINGLE} settings are
942 Case numbers start from 1. They are counted after all transformations
943 have been considered.
945 @cmd{LIST} is a procedure. It causes the data to be read.
955 @cmd{NEW FILE} command clears the dictionary and data from the current
964 [OUTFILE='@var{file_name}']
965 [RECORDS=@var{n_lines}]
967 [ENCODING='@var{encoding}']
968 [/[@var{line_no}] @var{arg}@dots{}]
970 @var{arg} takes one of the following forms:
971 '@var{string}' [@var{start}]
972 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
973 @var{var_list} (@var{fortran_spec})
977 The @cmd{PRINT} transformation writes variable data to the listing
978 file or an output file. @cmd{PRINT} is executed when a procedure
979 causes the data to be read. Follow @cmd{PRINT} by @cmd{EXECUTE} to
980 print variable data without invoking a procedure (@pxref{EXECUTE}).
982 All @cmd{PRINT} subcommands are optional. If no strings or variables
983 are specified, @cmd{PRINT} outputs a single blank line.
985 The @subcmd{OUTFILE} subcommand specifies the file to receive the output. The
986 file may be a file name as a string or a file handle (@pxref{File
987 Handles}). If @subcmd{OUTFILE} is not present then output will be sent to
988 @pspp{}'s output listing file. When @subcmd{OUTFILE} is present, a space is
989 inserted at beginning of each output line, even lines that otherwise
992 The @subcmd{ENCODING} subcommand may only be used if the
993 @subcmd{OUTFILE} subcommand is also used. It specifies the character
994 encoding of the file. @xref{INSERT}, for information on supported
997 The @subcmd{RECORDS} subcommand specifies the number of lines to be output. The
998 number of lines may optionally be surrounded by parentheses.
1000 @subcmd{TABLE} will cause the @cmd{PRINT} command to output a table to the listing file
1001 that describes what it will print to the output file. @subcmd{NOTABLE}, the
1002 default, suppresses this output table.
1004 Introduce the strings and variables to be printed with a slash
1005 (@samp{/}). Optionally, the slash may be followed by a number
1006 indicating which output line will be specified. In the absence of this
1007 line number, the next line number will be specified. Multiple lines may
1008 be specified using multiple slashes with the intended output for a line
1009 following its respective slash.
1011 Literal strings may be printed. Specify the string itself.
1012 Optionally the string may be followed by a column number, specifying
1013 the column on the line where the string should start. Otherwise, the
1014 string will be printed at the current position on the line.
1016 Variables to be printed can be specified in the same ways as available
1017 for @cmd{DATA LIST FIXED} (@pxref{DATA LIST FIXED}). In addition, a
1019 list may be followed by an asterisk (@samp{*}), which indicates that the
1020 variables should be printed in their dictionary print formats, separated
1021 by spaces. A variable list followed by a slash or the end of command
1022 will be interpreted the same way.
1024 If a FORTRAN type specification is used to move backwards on the current
1025 line, then text is written at that point on the line, the line will be
1026 truncated to that length, although additional text being added will
1027 again extend the line to that length.
1030 @section PRINT EJECT
1035 OUTFILE='@var{file_name}'
1036 RECORDS=@var{n_lines}
1038 /[@var{line_no}] @var{arg}@dots{}
1040 @var{arg} takes one of the following forms:
1041 '@var{string}' [@var{start}-@var{end}]
1042 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
1043 @var{var_list} (@var{fortran_spec})
1047 @cmd{PRINT EJECT} advances to the beginning of a new output page in
1048 the listing file or output file. It can also output data in the same
1051 All @cmd{PRINT EJECT} subcommands are optional.
1053 Without @subcmd{OUTFILE}, @cmd{PRINT EJECT} ejects the current page in
1054 the listing file, then it produces other output, if any is specified.
1056 With @subcmd{OUTFILE}, @cmd{PRINT EJECT} writes its output to the specified file.
1057 The first line of output is written with @samp{1} inserted in the
1058 first column. Commonly, this is the only line of output. If
1059 additional lines of output are specified, these additional lines are
1060 written with a space inserted in the first column, as with @subcmd{PRINT}.
1062 @xref{PRINT}, for more information on syntax and usage.
1065 @section PRINT SPACE
1069 PRINT SPACE [OUTFILE='file_name'] [ENCODING='@var{encoding}'] [n_lines].
1072 @cmd{PRINT SPACE} prints one or more blank lines to an output file.
1074 The @subcmd{OUTFILE} subcommand is optional. It may be used to direct output to
1075 a file specified by file name as a string or file handle (@pxref{File
1076 Handles}). If OUTFILE is not specified then output will be directed to
1079 The @subcmd{ENCODING} subcommand may only be used if @subcmd{OUTFILE}
1080 is also used. It specifies the character encoding of the file.
1081 @xref{INSERT}, for information on supported encodings.
1083 n_lines is also optional. If present, it is an expression
1084 (@pxref{Expressions}) specifying the number of blank lines to be
1085 printed. The expression must evaluate to a nonnegative value.
1092 REREAD [FILE=handle] [COLUMN=column] [ENCODING='@var{encoding}'].
1095 The @cmd{REREAD} transformation allows the previous input line in a
1097 already processed by @cmd{DATA LIST} or another input command to be re-read
1098 for further processing.
1100 The @subcmd{FILE} subcommand, which is optional, is used to specify the file to
1101 have its line re-read. The file must be specified as the name of a file
1102 handle (@pxref{File Handles}). If FILE is not specified then the last
1103 file specified on @cmd{DATA LIST} will be assumed (last file specified
1104 lexically, not in terms of flow-of-control).
1106 By default, the line re-read is re-read in its entirety. With the
1107 @subcmd{COLUMN} subcommand, a prefix of the line can be exempted from
1108 re-reading. Specify an expression (@pxref{Expressions}) evaluating to
1109 the first column that should be included in the re-read line. Columns
1110 are numbered from 1 at the left margin.
1112 The @subcmd{ENCODING} subcommand may only be used if the @subcmd{FILE}
1113 subcommand is also used. It specifies the character encoding of the
1114 file. @xref{INSERT}, for information on supported encodings.
1116 Issuing @code{REREAD} multiple times will not back up in the data
1117 file. Instead, it will re-read the same line multiple times.
1119 @node REPEATING DATA
1120 @section REPEATING DATA
1121 @vindex REPEATING DATA
1125 /STARTS=@var{start}-@var{end}
1126 /OCCURS=@var{n_occurs}
1127 /FILE='@var{file_name}'
1128 /LENGTH=@var{length}
1129 /CONTINUED[=@var{cont_start}-@var{cont_end}]
1130 /ID=@var{id_start}-@var{id_end}=@var{id_var}
1132 /DATA=@var{var_spec}@dots{}
1134 where each @var{var_spec} takes one of the forms
1135 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
1136 @var{var_list} (@var{fortran_spec})
1139 @cmd{REPEATING DATA} parses groups of data repeating in
1140 a uniform format, possibly with several groups on a single line. Each
1141 group of data corresponds with one case. @cmd{REPEATING DATA} may only be
1142 used within an @cmd{INPUT PROGRAM} structure (@pxref{INPUT PROGRAM}).
1143 When used with @cmd{DATA LIST}, it
1144 can be used to parse groups of cases that share a subset of variables
1145 but differ in their other data.
1147 The @subcmd{STARTS} subcommand is required. Specify a range of columns, using
1148 literal numbers or numeric variable names. This range specifies the
1149 columns on the first line that are used to contain groups of data. The
1150 ending column is optional. If it is not specified, then the record
1151 width of the input file is used. For the inline file (@pxref{BEGIN
1152 DATA}) this is 80 columns; for a file with fixed record widths it is the
1153 record width; for other files it is 1024 characters by default.
1155 The @subcmd{OCCURS} subcommand is required. It must be a number or the name of a
1156 numeric variable. Its value is the number of groups present in the
1159 The @subcmd{DATA} subcommand is required. It must be the last subcommand
1160 specified. It is used to specify the data present within each repeating
1161 group. Column numbers are specified relative to the beginning of a
1162 group at column 1. Data is specified in the same way as with @cmd{DATA LIST
1163 FIXED} (@pxref{DATA LIST FIXED}).
1165 All other subcommands are optional.
1167 FILE specifies the file to read, either a file name as a string or a
1168 file handle (@pxref{File Handles}). If FILE is not present then the
1169 default is the last file handle used on @cmd{DATA LIST} (lexically, not in
1170 terms of flow of control).
1172 By default @cmd{REPEATING DATA} will output a table describing how it will
1173 parse the input data. Specifying @subcmd{NOTABLE} will disable this behavior;
1174 specifying TABLE will explicitly enable it.
1176 The @subcmd{LENGTH} subcommand specifies the length in characters of each group.
1177 If it is not present then length is inferred from the @subcmd{DATA} subcommand.
1178 LENGTH can be a number or a variable name.
1180 Normally all the data groups are expected to be present on a single
1181 line. Use the @subcmd{CONTINUED} command to indicate that data can be continued
1182 onto additional lines. If data on continuation lines starts at the left
1183 margin and continues through the entire field width, no column
1184 specifications are necessary on @subcmd{CONTINUED}. Otherwise, specify the
1185 possible range of columns in the same way as on STARTS.
1187 When data groups are continued from line to line, it is easy
1188 for cases to get out of sync through careless hand editing. The
1189 @subcmd{ID} subcommand allows a case identifier to be present on each line of
1190 repeating data groups. @cmd{REPEATING DATA} will check for the same
1191 identifier on each line and report mismatches. Specify the range of
1192 columns that the identifier will occupy, followed by an equals sign
1193 (@samp{=}) and the identifier variable name. The variable must already
1194 have been declared with @cmd{NUMERIC} or another command.
1196 @cmd{REPEATING DATA} should be the last command given within an
1197 @cmd{INPUT PROGRAM}. It should not be enclosed within a @cmd{LOOP}
1198 structure (@pxref{LOOP}). Use @cmd{DATA LIST} before, not after,
1199 @cmd{REPEATING DATA}.
1207 OUTFILE='@var{file_name}'
1208 RECORDS=@var{n_lines}
1210 /[@var{line_no}] @var{arg}@dots{}
1212 @var{arg} takes one of the following forms:
1213 '@var{string}' [@var{start}-@var{end}]
1214 @var{var_list} @var{start}-@var{end} [@var{type_spec}]
1215 @var{var_list} (@var{fortran_spec})
1219 @code{WRITE} writes text or binary data to an output file.
1221 @xref{PRINT}, for more information on syntax and usage. @cmd{PRINT}
1222 and @cmd{WRITE} differ in only a few ways:
1226 @cmd{WRITE} uses write formats by default, whereas @cmd{PRINT} uses
1230 @cmd{PRINT} inserts a space between variables unless a format is
1231 explicitly specified, but @cmd{WRITE} never inserts space between
1232 variables in output.
1235 @cmd{PRINT} inserts a space at the beginning of each line that it
1236 writes to an output file (and @cmd{PRINT EJECT} inserts @samp{1} at
1237 the beginning of each line that should begin a new page), but
1238 @cmd{WRITE} does not.
1241 @cmd{PRINT} outputs the system-missing value according to its
1242 specified output format, whereas @cmd{WRITE} outputs the
1243 system-missing value as a field filled with spaces. Binary formats