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{})]
346 where each var_spec takes one of the forms
347 var_list [(type_spec)]
351 In free format, the input data is, by default, structured as a series
352 of fields separated by spaces, tabs, commas, or line breaks. Each
353 field's content may be unquoted, or it may be quoted with a pairs of
354 apostrophes (@samp{'}) or double quotes (@samp{"}). Unquoted white
355 space separates fields but is not part of any field. Any mix of
356 spaces, tabs, and line breaks is equivalent to a single space for the
357 purpose of separating fields, but consecutive commas will skip a
360 Alternatively, delimiters can be specified explicitly, as a
361 parenthesized, comma-separated list of single-character strings
362 immediately following FREE. The word TAB may also be used to specify
363 a tab character as a delimiter. When delimiters are specified
364 explicitly, only the given characters, plus line breaks, separate
365 fields. Furthermore, leading spaces at the beginnings of fields are
366 not trimmed, consecutive delimiters define empty fields, and no form
367 of quoting is allowed.
369 The NOTABLE and TABLE subcommands are as in @cmd{DATA LIST FIXED} above.
370 NOTABLE is the default.
372 The FILE, END, and SKIP subcommands are as in @cmd{DATA LIST FIXED} above.
374 The variables to be parsed are given as a single list of variable names.
375 This list must be introduced by a single slash (@samp{/}). The set of
376 variable names may contain format specifications in parentheses
377 (@pxref{Input and Output Formats}). Format specifications apply to all
378 variables back to the previous parenthesized format specification.
380 In addition, an asterisk may be used to indicate that all variables
381 preceding it are to have input/output format @samp{F8.0}.
383 Specified field widths are ignored on input, although all normal limits
384 on field width apply, but they are honored on output.
387 @subsection DATA LIST LIST
388 @vindex DATA LIST LIST
392 [(@{TAB,'c'@}, @dots{})]
399 where each var_spec takes one of the forms
400 var_list [(type_spec)]
404 With one exception, @cmd{DATA LIST LIST} is syntactically and
405 semantically equivalent to @cmd{DATA LIST FREE}. The exception is
406 that each input line is expected to correspond to exactly one input
407 record. If more or fewer fields are found on an input line than
408 expected, an appropriate diagnostic is issued.
418 @cmd{END CASE} is used only within @cmd{INPUT PROGRAM} to output the
419 current case. @xref{INPUT PROGRAM}, for details.
429 @cmd{END FILE} is used only within @cmd{INPUT PROGRAM} to terminate
430 the current input program. @xref{INPUT PROGRAM}.
438 FILE HANDLE handle_name
443 For binary files with fixed-length records:
444 FILE HANDLE handle_name
449 To explicitly declare a scratch handle:
450 FILE HANDLE handle_name
454 Use @cmd{FILE HANDLE} to associate a file handle name with a file and
455 its attributes, so that later commands can refer to the file by its
456 handle name. Names of text files can be specified directly on
457 commands that access files, so that @cmd{FILE HANDLE} is only needed when a
458 file is not an ordinary file containing lines of text. However,
459 @cmd{FILE HANDLE} may be used even for text files, and it may be
460 easier to specify a file's name once and later refer to it by an
463 Specify the file handle name as the identifier immediately following the
464 @cmd{FILE HANDLE} command name. The identifier INLINE is reserved for
465 representing data embedded in the syntax file (@pxref{BEGIN DATA}) The
466 file handle name must not already have been used in a previous
467 invocation of @cmd{FILE HANDLE}, unless it has been closed by an
468 intervening command (@pxref{CLOSE FILE HANDLE}).
470 MODE specifies a file mode. In CHARACTER mode, the default, the data
471 file is read as a text file, according to the local system's
472 conventions, and each text line is read as one record.
473 In CHARACTER mode, most input programs will expand tabs to spaces
474 (@cmd{DATA LIST FREE} with explicitly specified delimiters is an
475 exception). By default, each tab is 4 characters wide, but an
476 alternate width may be specified on TABWIDTH. A tab width of 0
477 suppresses tab expansion entirely.
479 In IMAGE mode, the data file is opened in ANSI C binary mode. Record
480 length is fixed, with output data truncated or padded with spaces to
481 the record length. LRECL specifies the record length in bytes, with a
482 default of 1024. Tab characters are never expanded to spaces in
485 The NAME subcommand specifies the name of the file associated with the
486 handle. It is required in CHARACTER and IMAGE modes.
488 The SCRATCH mode designates the file handle as a scratch file handle.
489 Its use is usually unnecessary because file handle names that begin with
490 @samp{#} are assumed to refer to scratch files. @pxref{File Handles},
491 for more information.
494 @section INPUT PROGRAM
495 @vindex INPUT PROGRAM
499 @dots{} input commands @dots{}
503 @cmd{INPUT PROGRAM}@dots{}@cmd{END INPUT PROGRAM} specifies a
504 complex input program. By placing data input commands within @cmd{INPUT
505 PROGRAM}, PSPP programs can take advantage of more complex file
506 structures than available with only @cmd{DATA LIST}.
508 The first sort of extended input program is to simply put multiple @cmd{DATA
509 LIST} commands within the @cmd{INPUT PROGRAM}. This will cause all of
511 files to be read in parallel. Input will stop when end of file is
512 reached on any of the data files.
514 Transformations, such as conditional and looping constructs, can also be
515 included within @cmd{INPUT PROGRAM}. These can be used to combine input
516 from several data files in more complex ways. However, input will still
517 stop when end of file is reached on any of the data files.
519 To prevent @cmd{INPUT PROGRAM} from terminating at the first end of
521 the END subcommand on @cmd{DATA LIST}. This subcommand takes a
523 which should be a numeric scratch variable (@pxref{Scratch Variables}).
524 (It need not be a scratch variable but otherwise the results can be
525 surprising.) The value of this variable is set to 0 when reading the
526 data file, or 1 when end of file is encountered.
528 Two additional commands are useful in conjunction with @cmd{INPUT PROGRAM}.
529 @cmd{END CASE} is the first. Normally each loop through the
531 structure produces one case. @cmd{END CASE} controls exactly
532 when cases are output. When @cmd{END CASE} is used, looping from the end of
533 @cmd{INPUT PROGRAM} to the beginning does not cause a case to be output.
535 @cmd{END FILE} is the second. When the END subcommand is used on @cmd{DATA
536 LIST}, there is no way for the @cmd{INPUT PROGRAM} construct to stop
538 so an infinite loop results. @cmd{END FILE}, when executed,
539 stops the flow of input data and passes out of the @cmd{INPUT PROGRAM}
542 All this is very confusing. A few examples should help to clarify.
544 @c If you change this example, change the regression test1 in
545 @c tests/command/input-program.sh to match.
548 DATA LIST NOTABLE FILE='a.data'/X 1-10.
549 DATA LIST NOTABLE FILE='b.data'/Y 1-10.
554 The example above reads variable X from file @file{a.data} and variable
555 Y from file @file{b.data}. If one file is shorter than the other then
556 the extra data in the longer file is ignored.
558 @c If you change this example, change the regression test2 in
559 @c tests/command/input-program.sh to match.
565 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
568 DATA LIST NOTABLE END=#B FILE='b.data'/Y 1-10.
578 The above example reads variable X from @file{a.data} and variable Y from
579 @file{b.data}. If one file is shorter than the other then the missing
580 field is set to the system-missing value alongside the present value for
581 the remaining length of the longer file.
583 @c If you change this example, change the regression test3 in
584 @c tests/command/input-program.sh to match.
590 DATA LIST NOTABLE END=#B FILE='b.data'/X 1-10.
597 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
606 The above example reads data from file @file{a.data}, then from
607 @file{b.data}, and concatenates them into a single active file.
609 @c If you change this example, change the regression test4 in
610 @c tests/command/input-program.sh to match.
616 DATA LIST NOTABLE END=#EOF FILE='a.data'/X 1-10.
624 DATA LIST NOTABLE END=#EOF FILE='b.data'/X 1-10.
635 The above example does the same thing as the previous example, in a
638 @c If you change this example, make similar changes to the regression
639 @c test5 in tests/command/input-program.sh.
643 COMPUTE X=UNIFORM(10).
648 LIST/FORMAT=NUMBERED.
651 The above example causes an active file to be created consisting of 50
652 random variates between 0 and 10.
661 /CASES=FROM start_index TO end_index BY incr_index
662 /FORMAT=@{UNNUMBERED,NUMBERED@} @{WRAP,SINGLE@}
666 The @cmd{LIST} procedure prints the values of specified variables to the
669 The VARIABLES subcommand specifies the variables whose values are to be
670 printed. Keyword VARIABLES is optional. If VARIABLES subcommand is not
671 specified then all variables in the active file are printed.
673 The CASES subcommand can be used to specify a subset of cases to be
674 printed. Specify FROM and the case number of the first case to print,
675 TO and the case number of the last case to print, and BY and the number
676 of cases to advance between printing cases, or any subset of those
677 settings. If CASES is not specified then all cases are printed.
679 The FORMAT subcommand can be used to change the output format. NUMBERED
680 will print case numbers along with each case; UNNUMBERED, the default,
681 causes the case numbers to be omitted. The WRAP and SINGLE settings are
682 currently not used. WEIGHT will cause case weights to be printed along
683 with variable values; NOWEIGHT, the default, causes case weights to be
684 omitted from the output.
686 Case numbers start from 1. They are counted after all transformations
687 have been considered.
689 @cmd{LIST} attempts to fit all the values on a single line. If needed
690 to make them fit, variable names are displayed vertically. If values
691 cannot fit on a single line, then a multi-line format will be used.
693 @cmd{LIST} is a procedure. It causes the data to be read.
703 @cmd{NEW FILE} command clears the current active file.
714 [/[line_no] arg@dots{}]
716 arg takes one of the following forms:
718 var_list start-end [type_spec]
719 var_list (fortran_spec)
723 The @cmd{PRINT} transformation writes variable data to the listing
724 file or an output file. @cmd{PRINT} is executed when a procedure
725 causes the data to be read. Follow @cmd{PRINT} by @cmd{EXECUTE} to
726 print variable data without invoking a procedure (@pxref{EXECUTE}).
728 All @cmd{PRINT} subcommands are optional. If no strings or variables
729 are specified, PRINT outputs a single blank line.
731 The OUTFILE subcommand specifies the file to receive the output. The
732 file may be a file name as a string or a file handle (@pxref{File
733 Handles}). If OUTFILE is not present then output will be sent to
734 PSPP's output listing file. When OUTFILE is present, a space is
735 inserted at beginning of each output line, even lines that otherwise
738 The RECORDS subcommand specifies the number of lines to be output. The
739 number of lines may optionally be surrounded by parentheses.
741 TABLE will cause the PRINT command to output a table to the listing file
742 that describes what it will print to the output file. NOTABLE, the
743 default, suppresses this output table.
745 Introduce the strings and variables to be printed with a slash
746 (@samp{/}). Optionally, the slash may be followed by a number
747 indicating which output line will be specified. In the absence of this
748 line number, the next line number will be specified. Multiple lines may
749 be specified using multiple slashes with the intended output for a line
750 following its respective slash.
752 Literal strings may be printed. Specify the string itself. Optionally
753 the string may be followed by a column number or range of column
754 numbers, specifying the location on the line for the string to be
755 printed. Otherwise, the string will be printed at the current position
758 Variables to be printed can be specified in the same ways as available
759 for @cmd{DATA LIST FIXED} (@pxref{DATA LIST FIXED}). In addition, a
761 list may be followed by an asterisk (@samp{*}), which indicates that the
762 variables should be printed in their dictionary print formats, separated
763 by spaces. A variable list followed by a slash or the end of command
764 will be interpreted the same way.
766 If a FORTRAN type specification is used to move backwards on the current
767 line, then text is written at that point on the line, the line will be
768 truncated to that length, although additional text being added will
769 again extend the line to that length.
780 /[line_no] arg@dots{}
782 arg takes one of the following forms:
784 var_list start-end [type_spec]
785 var_list (fortran_spec)
789 @cmd{PRINT EJECT} advances to the beginning of a new output page in
790 the listing file or output file. It can also output data in the same
793 All @cmd{PRINT EJECT} subcommands are optional.
795 Without OUTFILE, PRINT EJECT ejects the current page in
796 the listing file, then it produces other output, if any is specified.
798 With OUTFILE, PRINT EJECT writes its output to the specified file.
799 The first line of output is written with @samp{1} inserted in the
800 first column. Commonly, this is the only line of output. If
801 additional lines of output are specified, these additional lines are
802 written with a space inserted in the first column, as with PRINT.
804 @xref{PRINT}, for more information on syntax and usage.
811 PRINT SPACE OUTFILE='file-name' n_lines.
814 @cmd{PRINT SPACE} prints one or more blank lines to an output file.
816 The OUTFILE subcommand is optional. It may be used to direct output to
817 a file specified by file name as a string or file handle (@pxref{File
818 Handles}). If OUTFILE is not specified then output will be directed to
821 n_lines is also optional. If present, it is an expression
822 (@pxref{Expressions}) specifying the number of blank lines to be
823 printed. The expression must evaluate to a nonnegative value.
830 REREAD FILE=handle COLUMN=column.
833 The @cmd{REREAD} transformation allows the previous input line in a
835 already processed by @cmd{DATA LIST} or another input command to be re-read
836 for further processing.
838 The FILE subcommand, which is optional, is used to specify the file to
839 have its line re-read. The file must be specified as the name of a file
840 handle (@pxref{File Handles}). If FILE is not specified then the last
841 file specified on @cmd{DATA LIST} will be assumed (last file specified
842 lexically, not in terms of flow-of-control).
844 By default, the line re-read is re-read in its entirety. With the
845 COLUMN subcommand, a prefix of the line can be exempted from
846 re-reading. Specify an expression (@pxref{Expressions}) evaluating to
847 the first column that should be included in the re-read line. Columns
848 are numbered from 1 at the left margin.
850 Issuing @code{REREAD} multiple times will not back up in the data
851 file. Instead, it will re-read the same line multiple times.
854 @section REPEATING DATA
855 @vindex REPEATING DATA
863 /CONTINUED[=cont_start-cont_end]
864 /ID=id_start-id_end=id_var
866 /DATA=var_spec@dots{}
868 where each var_spec takes one of the forms
869 var_list start-end [type_spec]
870 var_list (fortran_spec)
873 @cmd{REPEATING DATA} parses groups of data repeating in
874 a uniform format, possibly with several groups on a single line. Each
875 group of data corresponds with one case. @cmd{REPEATING DATA} may only be
876 used within an @cmd{INPUT PROGRAM} structure (@pxref{INPUT PROGRAM}).
877 When used with @cmd{DATA LIST}, it
878 can be used to parse groups of cases that share a subset of variables
879 but differ in their other data.
881 The STARTS subcommand is required. Specify a range of columns, using
882 literal numbers or numeric variable names. This range specifies the
883 columns on the first line that are used to contain groups of data. The
884 ending column is optional. If it is not specified, then the record
885 width of the input file is used. For the inline file (@pxref{BEGIN
886 DATA}) this is 80 columns; for a file with fixed record widths it is the
887 record width; for other files it is 1024 characters by default.
889 The OCCURS subcommand is required. It must be a number or the name of a
890 numeric variable. Its value is the number of groups present in the
893 The DATA subcommand is required. It must be the last subcommand
894 specified. It is used to specify the data present within each repeating
895 group. Column numbers are specified relative to the beginning of a
896 group at column 1. Data is specified in the same way as with @cmd{DATA LIST
897 FIXED} (@pxref{DATA LIST FIXED}).
899 All other subcommands are optional.
901 FILE specifies the file to read, either a file name as a string or a
902 file handle (@pxref{File Handles}). If FILE is not present then the
903 default is the last file handle used on @cmd{DATA LIST} (lexically, not in
904 terms of flow of control).
906 By default @cmd{REPEATING DATA} will output a table describing how it will
907 parse the input data. Specifying NOTABLE will disable this behavior;
908 specifying TABLE will explicitly enable it.
910 The LENGTH subcommand specifies the length in characters of each group.
911 If it is not present then length is inferred from the DATA subcommand.
912 LENGTH can be a number or a variable name.
914 Normally all the data groups are expected to be present on a single
915 line. Use the CONTINUED command to indicate that data can be continued
916 onto additional lines. If data on continuation lines starts at the left
917 margin and continues through the entire field width, no column
918 specifications are necessary on CONTINUED. Otherwise, specify the
919 possible range of columns in the same way as on STARTS.
921 When data groups are continued from line to line, it is easy
922 for cases to get out of sync through careless hand editing. The
923 ID subcommand allows a case identifier to be present on each line of
924 repeating data groups. @cmd{REPEATING DATA} will check for the same
925 identifier on each line and report mismatches. Specify the range of
926 columns that the identifier will occupy, followed by an equals sign
927 (@samp{=}) and the identifier variable name. The variable must already
928 have been declared with @cmd{NUMERIC} or another command.
930 @cmd{REPEATING DATA} should be the last command given within an
931 @cmd{INPUT PROGRAM}. It should not be enclosed within a @cmd{LOOP}
932 structure (@pxref{LOOP}). Use @cmd{DATA LIST} before, not after,
933 @cmd{REPEATING DATA}.
944 /[line_no] arg@dots{}
946 arg takes one of the following forms:
948 var_list start-end [type_spec]
949 var_list (fortran_spec)
953 @code{WRITE} writes text or binary data to an output file.
955 @xref{PRINT}, for more information on syntax and usage. @cmd{PRINT}
956 and @cmd{WRITE} differ in only a few ways:
960 @cmd{WRITE} uses write formats by default, whereas @cmd{PRINT} uses
964 @cmd{PRINT} inserts a space between variables unless a format is
965 explicitly specified, but @cmd{WRITE} never inserts space between
969 @cmd{PRINT} inserts a space at the beginning of each line that it
970 writes to an output file (and @cmd{PRINT EJECT} inserts @samp{1} at
971 the beginning of each line that should begin a new page), but
972 @cmd{WRITE} does not.
975 @cmd{PRINT} outputs the system-missing value according to its
976 specified output format, whereas @cmd{WRITE} outputs the
977 system-missing value as a field filled with spaces. Binary formats