1 @node Data Input and Output
2 @chapter Data Input and Output
9 Data are the focus of the PSPP language.
10 Each datum belongs to a @dfn{case} (also called an @dfn{observation}).
11 Each case represents an individual or ``experimental unit''.
12 For example, in the results of a survey, the names of the respondents,
13 their sex, age, etc.@: and their responses are all data and the data
14 pertaining to single respondent is a case.
16 the PSPP commands for defining variables and reading and writing data.
19 These commands tell PSPP how to read data, but the data will not
20 actually be read until a procedure is executed.
24 * BEGIN DATA:: Embed data within a syntax file.
25 * CLOSE FILE HANDLE:: Close a file handle.
26 * DATA LIST:: Fundamental data reading command.
27 * END CASE:: Output the current case.
28 * END FILE:: Terminate the current input program.
29 * FILE HANDLE:: Support for special file formats.
30 * INPUT PROGRAM:: Support for complex input programs.
31 * LIST:: List cases in the active file.
32 * NEW FILE:: Clear the active file and dictionary.
33 * PRINT:: Display values in print formats.
34 * PRINT EJECT:: Eject the current page then print.
35 * PRINT SPACE:: Print blank lines.
36 * REREAD:: Take another look at the previous input line.
37 * REPEATING DATA:: Multiple cases on a single line.
38 * WRITE:: Display values in write formats.
45 @cindex Embedding data in syntax files
46 @cindex Data, embedding in syntax files
54 @cmd{BEGIN DATA} and @cmd{END DATA} can be used to embed raw ASCII
55 data in a PSPP syntax file. @cmd{DATA LIST} or another input
56 procedure must be used before @cmd{BEGIN DATA} (@pxref{DATA LIST}).
57 @cmd{BEGIN DATA} and @cmd{END DATA} must be used together. @cmd{END
58 DATA} must appear by itself on a single line, with no leading
59 white space and exactly one space between the words @code{END} and
60 @code{DATA}, like this:
66 @node CLOSE FILE HANDLE
67 @section CLOSE FILE HANDLE
70 CLOSE FILE HANDLE handle_name.
73 @cmd{CLOSE FILE HANDLE} disassociates the name of a file handle with a
74 given file. The only specification is the name of the handle to close.
78 If the file handle name refers to a scratch file, then the storage
79 associated with the scratch file in memory or on disk will be freed.
80 If the scratch file is in use, e.g.@: it has been specified on a
81 @cmd{GET} command whose execution has not completed, then freeing is
82 delayed until it is no longer in use.
84 The file named INLINE, which represents data entered between @cmd{BEGIN
85 DATA} and @cmd{END DATA}, cannot be closed. Attempts to close it with
86 @cmd{CLOSE FILE HANDLE} have no effect.
88 @cmd{CLOSE FILE HANDLE} is a PSPP extension.
93 @cindex reading data from a file
94 @cindex data, reading from a file
95 @cindex data, embedding in syntax files
96 @cindex embedding data in syntax files
98 Used to read text or binary data, @cmd{DATA LIST} is the most
99 fundamental data-reading command. Even the more sophisticated input
100 methods use @cmd{DATA LIST} commands as a building block.
101 Understanding @cmd{DATA LIST} is important to understanding how to use
102 PSPP to read your data files.
104 There are two major variants of @cmd{DATA LIST}, which are fixed
105 format and free format. In addition, free format has a minor variant,
106 list format, which is discussed in terms of its differences from vanilla
109 Each form of @cmd{DATA LIST} is described in detail below.
112 * DATA LIST FIXED:: Fixed columnar locations for data.
113 * DATA LIST FREE:: Any spacing you like.
114 * DATA LIST LIST:: Each case must be on a single line.
117 @node DATA LIST FIXED
118 @subsection DATA LIST FIXED
119 @vindex DATA LIST FIXED
120 @cindex reading fixed-format data
121 @cindex fixed-format data, reading
122 @cindex data, fixed-format, reading
123 @cindex embedding fixed-format data
129 [RECORDS=record_count]
132 /[line_no] var_spec@dots{}
134 where each var_spec takes one of the forms
135 var_list start-end [type_spec]
136 var_list (fortran_spec)
139 @cmd{DATA LIST FIXED} is used to read data files that have values at fixed
140 positions on each line of single-line or multiline records. The
141 keyword FIXED is optional.
143 The FILE subcommand must be used if input is to be taken from an
144 external file. It may be used to specify a file name as a string or a
145 file handle (@pxref{File Handles}). If the FILE subcommand is not used,
146 then input is assumed to be specified within the command file using
147 @cmd{BEGIN DATA}@dots{}@cmd{END DATA} (@pxref{BEGIN DATA}).
149 The optional RECORDS subcommand, which takes a single integer as an
150 argument, is used to specify the number of lines per record. If RECORDS
151 is not specified, then the number of lines per record is calculated from
152 the list of variable specifications later in @cmd{DATA LIST}.
154 The END subcommand is only useful in conjunction with @cmd{INPUT
155 PROGRAM}. @xref{INPUT PROGRAM}, for details.
157 The optional SKIP subcommand specifies a number of records to skip at
158 the beginning of an input file. It can be used to skip over a row
159 that contains variable names, for example.
161 @cmd{DATA LIST} can optionally output a table describing how the data file
162 will be read. The TABLE subcommand enables this output, and NOTABLE
163 disables it. The default is to output the table.
165 The list of variables to be read from the data list must come last.
166 Each line in the data record is introduced by a slash (@samp{/}).
167 Optionally, a line number may follow the slash. Following, any number
168 of variable specifications may be present.
170 Each variable specification consists of a list of variable names
171 followed by a description of their location on the input line. Sets of
172 variables may be specified using the @code{DATA LIST} TO convention
174 Variables}). There are two ways to specify the location of the variable
175 on the line: columnar style and FORTRAN style.
177 In columnar style, the starting column and ending column for the field
178 are specified after the variable name, separated by a dash (@samp{-}).
179 For instance, the third through fifth columns on a line would be
180 specified @samp{3-5}. By default, variables are considered to be in
181 @samp{F} format (@pxref{Input and Output Formats}). (This default can be
182 changed; see @ref{SET} for more information.)
184 In columnar style, to use a variable format other than the default,
185 specify the format type in parentheses after the column numbers. For
186 instance, for alphanumeric @samp{A} format, use @samp{(A)}.
188 In addition, implied decimal places can be specified in parentheses
189 after the column numbers. As an example, suppose that a data file has a
190 field in which the characters @samp{1234} should be interpreted as
191 having the value 12.34. Then this field has two implied decimal places,
192 and the corresponding specification would be @samp{(2)}. If a field
193 that has implied decimal places contains a decimal point, then the
194 implied decimal places are not applied.
196 Changing the variable format and adding implied decimal places can be
197 done together; for instance, @samp{(N,5)}.
199 When using columnar style, the input and output width of each variable is
200 computed from the field width. The field width must be evenly divisible
201 into the number of variables specified.
203 FORTRAN style is an altogether different approach to specifying field
204 locations. With this approach, a list of variable input format
205 specifications, separated by commas, are placed after the variable names
206 inside parentheses. Each format specifier advances as many characters
207 into the input line as it uses.
209 Implied decimal places also exist in FORTRAN style. A format
210 specification with @var{d} decimal places also has @var{d} implied
213 In addition to the standard format specifiers (@pxref{Input and Output
214 Formats}), FORTRAN style defines some extensions:
218 Advance the current column on this line by one character position.
220 @item @code{T}@var{x}
221 Set the current column on this line to column @var{x}, with column
222 numbers considered to begin with 1 at the left margin.
224 @item @code{NEWREC}@var{x}
225 Skip forward @var{x} lines in the current record, resetting the active
226 column to the left margin.
229 Any format specifier may be preceded by a number. This causes the
230 action of that format specifier to be repeated the specified number of
233 @item (@var{spec1}, @dots{}, @var{specN})
234 Group the given specifiers together. This is most useful when preceded
235 by a repeat count. Groups may be nested arbitrarily.
238 FORTRAN and columnar styles may be freely intermixed. Columnar style
239 leaves the active column immediately after the ending column
240 specified. Record motion using @code{NEWREC} in FORTRAN style also
241 applies to later FORTRAN and columnar specifiers.
244 * DATA LIST FIXED Examples:: Examples of DATA LIST FIXED.
247 @node DATA LIST FIXED Examples
248 @unnumberedsubsubsec Examples
253 DATA LIST TABLE /NAME 1-10 (A) INFO1 TO INFO3 12-17 (1).
262 Defines the following variables:
266 @code{NAME}, a 10-character-wide long string variable, in columns 1
270 @code{INFO1}, a numeric variable, in columns 12 through 13.
273 @code{INFO2}, a numeric variable, in columns 14 through 15.
276 @code{INFO3}, a numeric variable, in columns 16 through 17.
279 The @code{BEGIN DATA}/@code{END DATA} commands cause three cases to be
283 Case NAME INFO1 INFO2 INFO3
284 1 John Smith 10 23 11
285 2 Bob Arnold 12 20 15
289 The @code{TABLE} keyword causes PSPP to print out a table
290 describing the four variables defined.
294 DAT LIS FIL="survey.dat"
295 /ID 1-5 NAME 7-36 (A) SURNAME 38-67 (A) MINITIAL 69 (A)
300 Defines the following variables:
304 @code{ID}, a numeric variable, in columns 1-5 of the first record.
307 @code{NAME}, a 30-character long string variable, in columns 7-36 of the
311 @code{SURNAME}, a 30-character long string variable, in columns 38-67 of
315 @code{MINITIAL}, a 1-character short string variable, in column 69 of
319 Fifty variables @code{Q01}, @code{Q02}, @code{Q03}, @dots{}, @code{Q49},
320 @code{Q50}, all numeric, @code{Q01} in column 7, @code{Q02} in column 8,
321 @dots{}, @code{Q49} in column 55, @code{Q50} in column 56, all in the second
325 Cases are separated by a blank record.
327 Data is read from file @file{survey.dat} in the current directory.
329 This example shows keywords abbreviated to their first 3 letters.
334 @subsection DATA LIST FREE
335 @vindex DATA LIST FREE
339 [(@{TAB,'c'@}, @dots{})]
345 where each var_spec takes one of the forms
346 var_list [(type_spec)]
350 In free format, the input data is, by default, structured as a series
351 of fields separated by spaces, tabs, commas, or line breaks. Each
352 field's content may be unquoted, or it may be quoted with a pairs of
353 apostrophes (@samp{'}) or double quotes (@samp{"}). Unquoted white
354 space separates fields but is not part of any field. Any mix of
355 spaces, tabs, and line breaks is equivalent to a single space for the
356 purpose of separating fields, but consecutive commas will skip a
359 Alternatively, delimiters can be specified explicitly, as a
360 parenthesized, comma-separated list of single-character strings
361 immediately following FREE. The word TAB may also be used to specify
362 a tab character as a delimiter. When delimiters are specified
363 explicitly, only the given characters, plus line breaks, separate
364 fields. Furthermore, leading spaces at the beginnings of fields are
365 not trimmed, consecutive delimiters define empty fields, and no form
366 of quoting is allowed.
368 The NOTABLE and TABLE subcommands are as in @cmd{DATA LIST FIXED} above.
369 NOTABLE is the default.
371 The FILE and SKIP subcommands are as in @cmd{DATA LIST FIXED} above.
373 The variables to be parsed are given as a single list of variable names.
374 This list must be introduced by a single slash (@samp{/}). The set of
375 variable names may contain format specifications in parentheses
376 (@pxref{Input and Output Formats}). Format specifications apply to all
377 variables back to the previous parenthesized format specification.
379 In addition, an asterisk may be used to indicate that all variables
380 preceding it are to have input/output format @samp{F8.0}.
382 Specified field widths are ignored on input, although all normal limits
383 on field width apply, but they are honored on output.
386 @subsection DATA LIST LIST
387 @vindex DATA LIST LIST
391 [(@{TAB,'c'@}, @dots{})]
397 where each var_spec takes one of the forms
398 var_list [(type_spec)]
402 With one exception, @cmd{DATA LIST LIST} is syntactically and
403 semantically equivalent to @cmd{DATA LIST FREE}. The exception is
404 that each input line is expected to correspond to exactly one input
405 record. If more or fewer fields are found on an input line than
406 expected, an appropriate diagnostic is issued.
416 @cmd{END CASE} is used only within @cmd{INPUT PROGRAM} to output the
417 current case. @xref{INPUT PROGRAM}, for details.
427 @cmd{END FILE} is used only within @cmd{INPUT PROGRAM} to terminate
428 the current input program. @xref{INPUT PROGRAM}.
436 FILE HANDLE handle_name
441 For binary files in native encoding with fixed-length records:
442 FILE HANDLE handle_name
447 For binary files in native encoding with variable-length records:
448 FILE HANDLE handle_name
453 For binary files encoded in EBCDIC:
454 FILE HANDLE handle_name
457 /RECFORM=@{FIXED,VARIABLE,SPANNED@}
460 To explicitly declare a scratch handle:
461 FILE HANDLE handle_name
465 Use @cmd{FILE HANDLE} to associate a file handle name with a file and
466 its attributes, so that later commands can refer to the file by its
467 handle name. Names of text files can be specified directly on
468 commands that access files, so that @cmd{FILE HANDLE} is only needed when a
469 file is not an ordinary file containing lines of text. However,
470 @cmd{FILE HANDLE} may be used even for text files, and it may be
471 easier to specify a file's name once and later refer to it by an
474 Specify the file handle name as the identifier immediately following the
475 @cmd{FILE HANDLE} command name. The identifier INLINE is reserved for
476 representing data embedded in the syntax file (@pxref{BEGIN DATA}) The
477 file handle name must not already have been used in a previous
478 invocation of @cmd{FILE HANDLE}, unless it has been closed by an
479 intervening command (@pxref{CLOSE FILE HANDLE}).
481 The effect and syntax of FILE HANDLE depends on the selected MODE:
485 In CHARACTER mode, the default, the data file is read as a text file,
486 according to the local system's conventions, and each text line is
489 In CHARACTER mode only, tabs are expanded to spaces by input programs,
490 except by @cmd{DATA LIST FREE} with explicitly specified delimiters.
491 Each tab is 4 characters wide by default, but TABWIDTH (a PSPP
492 extension) may be used to specify an alternate width. Use a TABWIDTH
493 of 0 to suppress tab expansion.
496 In IMAGE mode, the data file is treated as a series of fixed-length
497 binary records. LRECL should be used to specify the record length in
498 bytes, with a default of 1024. On input, it is an error if an IMAGE
499 file's length is not a integer multiple of the record length. On
500 output, each record is padded with spaces or truncated, if necessary,
501 to make it exactly the correct length.
504 In BINARY mode, the data file is treated as a series of
505 variable-length binary records. LRECL may be specified, but its value
506 is ignored. The data for each record is both preceded and followed by
507 a 32-bit signed integer in little-endian byte order that specifies the
508 length of the record. (This redundancy permits records in these
509 files to be efficiently read in reverse order, although PSPP always
510 reads them in forward order.) The length does not include either
514 Mode 360 reads and writes files in formats first used for tapes in the
515 1960s on IBM mainframe operating systems and still supported today by
516 the modern successors of those operating systems. For more
517 information, see @cite{OS/400 Tape and Diskette Device Programming},
518 available on IBM's website.
520 Alphanumeric data in mode 360 files are encoded in EBCDIC. PSPP
521 translates EBCDIC to or from the host's native format as necessary on
522 input or output, using an ASCII/EBCDIC translation that is one-to-one,
523 so that a ``round trip'' from ASCII to EBCDIC back to ASCII, or vice
524 versa, always yields exactly the original data.
526 The RECFORM subcommand is required in mode 360. The precise file
527 format depends on its setting:
532 This record format is equivalent to IMAGE mode, except for EBCDIC
535 IBM documentation calls this @code{*F} (fixed-length, deblocked)
540 The file comprises a sequence of zero or more variable-length blocks.
541 Each block begins with a 4-byte @dfn{block descriptor word} (BDW).
542 The first two bytes of the BDW are an unsigned integer in big-endian
543 byte order that specifies the length of the block, including the BDW
544 itself. The other two bytes of the BDW are ignored on input and
545 written as zeros on output.
547 Following the BDW, the remainder of each block is a sequence of one or
548 more variable-length records, each of which in turn begins with a
549 4-byte @dfn{record descriptor word} (RDW) that has the same format as
550 the BDW. Following the RDW, the remainder of each record is the
553 The maximum length of a record in VARIABLE mode is 65,527 bytes:
554 65,535 bytes (the maximum value of a 16-bit unsigned integer), minus 4
555 bytes for the BDW, minus 4 bytes for the RDW.
557 In mode VARIABLE, LRECL specifies a maximum, not a fixed, record
558 length, in bytes. The default is 8,192.
560 IBM documentation calls this @code{*VB} (variable-length, blocked,
565 The file format is like that of VARIABLE mode, except that logical
566 records may be split among multiple physical records (called
567 @dfn{segments}) or blocks. In SPANNED mode, the third byte of each
568 RDW is called the segment control character (SCC). Odd SCC values
569 cause the segment to be appended to a record buffer maintained in
570 memory; even values also append the segment and then flush its
571 contents to the input procedure. Canonically, SCC value 0 designates
572 a record not spanned among multiple segments, and values 1 through 3
573 designate the first segment, the last segment, or an intermediate
574 segment, respectively, within a multi-segment record. The record
575 buffer is also flushed at end of file regardless of the final record's
578 The maximum length of a logical record in VARIABLE mode is limited
579 only by memory available to PSPP. Segments are limited to 65,527
580 bytes, as in VARIABLE mode.
582 This format is similar to what IBM documentation call @code{*VS}
583 (variable-length, deblocked, spanned) format.
586 In mode 360, fields of type A that extend beyond the end of a record
587 read from disk are padded with spaces in the host's native character
588 set, which are then translated from EBCDIC to the native character
589 set. Thus, when the host's native character set is based on ASCII,
590 these fields are effectively padded with character @code{X'80'}. This
591 wart is implemented for compatibility.
594 SCRATCH mode is a PSPP extension that designates the file handle as a
596 Its use is usually unnecessary because file handle names that begin with
597 @samp{#} are assumed to refer to scratch files. @pxref{File Handles},
598 for more information.
601 The NAME subcommand specifies the name of the file associated with the
602 handle. It is required in all modes but SCRATCH mode, in which its
606 @section INPUT PROGRAM
607 @vindex INPUT PROGRAM
611 @dots{} input commands @dots{}
615 @cmd{INPUT PROGRAM}@dots{}@cmd{END INPUT PROGRAM} specifies a
616 complex input program. By placing data input commands within @cmd{INPUT
617 PROGRAM}, PSPP programs can take advantage of more complex file
618 structures than available with only @cmd{DATA LIST}.
620 The first sort of extended input program is to simply put multiple @cmd{DATA
621 LIST} commands within the @cmd{INPUT PROGRAM}. This will cause all of
623 files to be read in parallel. Input will stop when end of file is
624 reached on any of the data files.
626 Transformations, such as conditional and looping constructs, can also be
627 included within @cmd{INPUT PROGRAM}. These can be used to combine input
628 from several data files in more complex ways. However, input will still
629 stop when end of file is reached on any of the data files.
631 To prevent @cmd{INPUT PROGRAM} from terminating at the first end of
633 the END subcommand on @cmd{DATA LIST}. This subcommand takes a
635 which should be a numeric scratch variable (@pxref{Scratch Variables}).
636 (It need not be a scratch variable but otherwise the results can be
637 surprising.) The value of this variable is set to 0 when reading the
638 data file, or 1 when end of file is encountered.
640 Two additional commands are useful in conjunction with @cmd{INPUT PROGRAM}.
641 @cmd{END CASE} is the first. Normally each loop through the
643 structure produces one case. @cmd{END CASE} controls exactly
644 when cases are output. When @cmd{END CASE} is used, looping from the end of
645 @cmd{INPUT PROGRAM} to the beginning does not cause a case to be output.
647 @cmd{END FILE} is the second. When the END subcommand is used on @cmd{DATA
648 LIST}, there is no way for the @cmd{INPUT PROGRAM} construct to stop
650 so an infinite loop results. @cmd{END FILE}, when executed,
651 stops the flow of input data and passes out of the @cmd{INPUT PROGRAM}
654 All this is very confusing. A few examples should help to clarify.
656 @c If you change this example, change the regression test1 in
657 @c tests/command/input-program.sh to match.
660 DATA LIST NOTABLE FILE='a.data'/X 1-10.
661 DATA LIST NOTABLE FILE='b.data'/Y 1-10.
666 The example above reads variable X from file @file{a.data} and variable
667 Y from file @file{b.data}. If one file is shorter than the other then
668 the extra data in the longer file is ignored.
670 @c If you change this example, change the regression test2 in
671 @c tests/command/input-program.sh to match.
677 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
680 DATA LIST NOTABLE END=#B FILE='b.data'/Y 1-10.
690 The above example reads variable X from @file{a.data} and variable Y from
691 @file{b.data}. If one file is shorter than the other then the missing
692 field is set to the system-missing value alongside the present value for
693 the remaining length of the longer file.
695 @c If you change this example, change the regression test3 in
696 @c tests/command/input-program.sh to match.
702 DATA LIST NOTABLE END=#B FILE='b.data'/X 1-10.
709 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
718 The above example reads data from file @file{a.data}, then from
719 @file{b.data}, and concatenates them into a single active file.
721 @c If you change this example, change the regression test4 in
722 @c tests/command/input-program.sh to match.
728 DATA LIST NOTABLE END=#EOF FILE='a.data'/X 1-10.
736 DATA LIST NOTABLE END=#EOF FILE='b.data'/X 1-10.
747 The above example does the same thing as the previous example, in a
750 @c If you change this example, make similar changes to the regression
751 @c test5 in tests/command/input-program.sh.
755 COMPUTE X=UNIFORM(10).
760 LIST/FORMAT=NUMBERED.
763 The above example causes an active file to be created consisting of 50
764 random variates between 0 and 10.
773 /CASES=FROM start_index TO end_index BY incr_index
774 /FORMAT=@{UNNUMBERED,NUMBERED@} @{WRAP,SINGLE@}
778 The @cmd{LIST} procedure prints the values of specified variables to the
781 The VARIABLES subcommand specifies the variables whose values are to be
782 printed. Keyword VARIABLES is optional. If VARIABLES subcommand is not
783 specified then all variables in the active file are printed.
785 The CASES subcommand can be used to specify a subset of cases to be
786 printed. Specify FROM and the case number of the first case to print,
787 TO and the case number of the last case to print, and BY and the number
788 of cases to advance between printing cases, or any subset of those
789 settings. If CASES is not specified then all cases are printed.
791 The FORMAT subcommand can be used to change the output format. NUMBERED
792 will print case numbers along with each case; UNNUMBERED, the default,
793 causes the case numbers to be omitted. The WRAP and SINGLE settings are
794 currently not used. WEIGHT will cause case weights to be printed along
795 with variable values; NOWEIGHT, the default, causes case weights to be
796 omitted from the output.
798 Case numbers start from 1. They are counted after all transformations
799 have been considered.
801 @cmd{LIST} attempts to fit all the values on a single line. If needed
802 to make them fit, variable names are displayed vertically. If values
803 cannot fit on a single line, then a multi-line format will be used.
805 @cmd{LIST} is a procedure. It causes the data to be read.
815 @cmd{NEW FILE} command clears the current active file.
826 [/[line_no] arg@dots{}]
828 arg takes one of the following forms:
830 var_list start-end [type_spec]
831 var_list (fortran_spec)
835 The @cmd{PRINT} transformation writes variable data to the listing
836 file or an output file. @cmd{PRINT} is executed when a procedure
837 causes the data to be read. Follow @cmd{PRINT} by @cmd{EXECUTE} to
838 print variable data without invoking a procedure (@pxref{EXECUTE}).
840 All @cmd{PRINT} subcommands are optional. If no strings or variables
841 are specified, PRINT outputs a single blank line.
843 The OUTFILE subcommand specifies the file to receive the output. The
844 file may be a file name as a string or a file handle (@pxref{File
845 Handles}). If OUTFILE is not present then output will be sent to
846 PSPP's output listing file. When OUTFILE is present, a space is
847 inserted at beginning of each output line, even lines that otherwise
850 The RECORDS subcommand specifies the number of lines to be output. The
851 number of lines may optionally be surrounded by parentheses.
853 TABLE will cause the PRINT command to output a table to the listing file
854 that describes what it will print to the output file. NOTABLE, the
855 default, suppresses this output table.
857 Introduce the strings and variables to be printed with a slash
858 (@samp{/}). Optionally, the slash may be followed by a number
859 indicating which output line will be specified. In the absence of this
860 line number, the next line number will be specified. Multiple lines may
861 be specified using multiple slashes with the intended output for a line
862 following its respective slash.
864 Literal strings may be printed. Specify the string itself. Optionally
865 the string may be followed by a column number or range of column
866 numbers, specifying the location on the line for the string to be
867 printed. Otherwise, the string will be printed at the current position
870 Variables to be printed can be specified in the same ways as available
871 for @cmd{DATA LIST FIXED} (@pxref{DATA LIST FIXED}). In addition, a
873 list may be followed by an asterisk (@samp{*}), which indicates that the
874 variables should be printed in their dictionary print formats, separated
875 by spaces. A variable list followed by a slash or the end of command
876 will be interpreted the same way.
878 If a FORTRAN type specification is used to move backwards on the current
879 line, then text is written at that point on the line, the line will be
880 truncated to that length, although additional text being added will
881 again extend the line to that length.
892 /[line_no] arg@dots{}
894 arg takes one of the following forms:
896 var_list start-end [type_spec]
897 var_list (fortran_spec)
901 @cmd{PRINT EJECT} advances to the beginning of a new output page in
902 the listing file or output file. It can also output data in the same
905 All @cmd{PRINT EJECT} subcommands are optional.
907 Without OUTFILE, PRINT EJECT ejects the current page in
908 the listing file, then it produces other output, if any is specified.
910 With OUTFILE, PRINT EJECT writes its output to the specified file.
911 The first line of output is written with @samp{1} inserted in the
912 first column. Commonly, this is the only line of output. If
913 additional lines of output are specified, these additional lines are
914 written with a space inserted in the first column, as with PRINT.
916 @xref{PRINT}, for more information on syntax and usage.
923 PRINT SPACE OUTFILE='file-name' n_lines.
926 @cmd{PRINT SPACE} prints one or more blank lines to an output file.
928 The OUTFILE subcommand is optional. It may be used to direct output to
929 a file specified by file name as a string or file handle (@pxref{File
930 Handles}). If OUTFILE is not specified then output will be directed to
933 n_lines is also optional. If present, it is an expression
934 (@pxref{Expressions}) specifying the number of blank lines to be
935 printed. The expression must evaluate to a nonnegative value.
942 REREAD FILE=handle COLUMN=column.
945 The @cmd{REREAD} transformation allows the previous input line in a
947 already processed by @cmd{DATA LIST} or another input command to be re-read
948 for further processing.
950 The FILE subcommand, which is optional, is used to specify the file to
951 have its line re-read. The file must be specified as the name of a file
952 handle (@pxref{File Handles}). If FILE is not specified then the last
953 file specified on @cmd{DATA LIST} will be assumed (last file specified
954 lexically, not in terms of flow-of-control).
956 By default, the line re-read is re-read in its entirety. With the
957 COLUMN subcommand, a prefix of the line can be exempted from
958 re-reading. Specify an expression (@pxref{Expressions}) evaluating to
959 the first column that should be included in the re-read line. Columns
960 are numbered from 1 at the left margin.
962 Issuing @code{REREAD} multiple times will not back up in the data
963 file. Instead, it will re-read the same line multiple times.
966 @section REPEATING DATA
967 @vindex REPEATING DATA
975 /CONTINUED[=cont_start-cont_end]
976 /ID=id_start-id_end=id_var
978 /DATA=var_spec@dots{}
980 where each var_spec takes one of the forms
981 var_list start-end [type_spec]
982 var_list (fortran_spec)
985 @cmd{REPEATING DATA} parses groups of data repeating in
986 a uniform format, possibly with several groups on a single line. Each
987 group of data corresponds with one case. @cmd{REPEATING DATA} may only be
988 used within an @cmd{INPUT PROGRAM} structure (@pxref{INPUT PROGRAM}).
989 When used with @cmd{DATA LIST}, it
990 can be used to parse groups of cases that share a subset of variables
991 but differ in their other data.
993 The STARTS subcommand is required. Specify a range of columns, using
994 literal numbers or numeric variable names. This range specifies the
995 columns on the first line that are used to contain groups of data. The
996 ending column is optional. If it is not specified, then the record
997 width of the input file is used. For the inline file (@pxref{BEGIN
998 DATA}) this is 80 columns; for a file with fixed record widths it is the
999 record width; for other files it is 1024 characters by default.
1001 The OCCURS subcommand is required. It must be a number or the name of a
1002 numeric variable. Its value is the number of groups present in the
1005 The DATA subcommand is required. It must be the last subcommand
1006 specified. It is used to specify the data present within each repeating
1007 group. Column numbers are specified relative to the beginning of a
1008 group at column 1. Data is specified in the same way as with @cmd{DATA LIST
1009 FIXED} (@pxref{DATA LIST FIXED}).
1011 All other subcommands are optional.
1013 FILE specifies the file to read, either a file name as a string or a
1014 file handle (@pxref{File Handles}). If FILE is not present then the
1015 default is the last file handle used on @cmd{DATA LIST} (lexically, not in
1016 terms of flow of control).
1018 By default @cmd{REPEATING DATA} will output a table describing how it will
1019 parse the input data. Specifying NOTABLE will disable this behavior;
1020 specifying TABLE will explicitly enable it.
1022 The LENGTH subcommand specifies the length in characters of each group.
1023 If it is not present then length is inferred from the DATA subcommand.
1024 LENGTH can be a number or a variable name.
1026 Normally all the data groups are expected to be present on a single
1027 line. Use the CONTINUED command to indicate that data can be continued
1028 onto additional lines. If data on continuation lines starts at the left
1029 margin and continues through the entire field width, no column
1030 specifications are necessary on CONTINUED. Otherwise, specify the
1031 possible range of columns in the same way as on STARTS.
1033 When data groups are continued from line to line, it is easy
1034 for cases to get out of sync through careless hand editing. The
1035 ID subcommand allows a case identifier to be present on each line of
1036 repeating data groups. @cmd{REPEATING DATA} will check for the same
1037 identifier on each line and report mismatches. Specify the range of
1038 columns that the identifier will occupy, followed by an equals sign
1039 (@samp{=}) and the identifier variable name. The variable must already
1040 have been declared with @cmd{NUMERIC} or another command.
1042 @cmd{REPEATING DATA} should be the last command given within an
1043 @cmd{INPUT PROGRAM}. It should not be enclosed within a @cmd{LOOP}
1044 structure (@pxref{LOOP}). Use @cmd{DATA LIST} before, not after,
1045 @cmd{REPEATING DATA}.
1056 /[line_no] arg@dots{}
1058 arg takes one of the following forms:
1059 'string' [start-end]
1060 var_list start-end [type_spec]
1061 var_list (fortran_spec)
1065 @code{WRITE} writes text or binary data to an output file.
1067 @xref{PRINT}, for more information on syntax and usage. @cmd{PRINT}
1068 and @cmd{WRITE} differ in only a few ways:
1072 @cmd{WRITE} uses write formats by default, whereas @cmd{PRINT} uses
1076 @cmd{PRINT} inserts a space between variables unless a format is
1077 explicitly specified, but @cmd{WRITE} never inserts space between
1078 variables in output.
1081 @cmd{PRINT} inserts a space at the beginning of each line that it
1082 writes to an output file (and @cmd{PRINT EJECT} inserts @samp{1} at
1083 the beginning of each line that should begin a new page), but
1084 @cmd{WRITE} does not.
1087 @cmd{PRINT} outputs the system-missing value according to its
1088 specified output format, whereas @cmd{WRITE} outputs the
1089 system-missing value as a field filled with spaces. Binary formats
1092 @setfilename ignored