1 @node Data Input and Output, System and Portable Files, Expressions, Top
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 @i{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 @strong{Please note:} Data is not actually read until a procedure is
20 executed. These commands tell PSPP how to read data, but they
21 do not @emph{cause} PSPP to read data.
25 * BEGIN DATA:: Embed data within a syntax file.
26 * CLEAR TRANSFORMATIONS:: Clear pending transformations.
27 * DATA LIST:: Fundamental data reading command.
28 * END CASE:: Output the current case.
29 * END FILE:: Terminate the current input program.
30 * FILE HANDLE:: Support for fixed-length records.
31 * INPUT PROGRAM:: Support for complex input programs.
32 * LIST:: List cases in the active file.
33 * MATRIX DATA:: Read matrices in text format.
34 * NEW FILE:: Clear the active file and dictionary.
35 * PRINT:: Display values in print formats.
36 * PRINT EJECT:: Eject the current page then print.
37 * PRINT SPACE:: Print blank lines.
38 * REREAD:: Take another look at the previous input line.
39 * REPEATING DATA:: Multiple cases on a single line.
40 * WRITE:: Display values in write formats.
43 @node BEGIN DATA, CLEAR TRANSFORMATIONS, Data Input and Output, Data Input and Output
47 @cindex Embedding data in syntax files
48 @cindex Data, embedding in syntax files
56 @cmd{BEGIN DATA} and @cmd{END DATA} can be used to embed raw ASCII
57 data in a PSPP syntax file. @cmd{DATA LIST} or another input
58 procedure must be used before @cmd{BEGIN DATA} (@pxref{DATA LIST}).
59 @cmd{BEGIN DATA} and @cmd{END DATA} must be used together. @cmd{END
60 DATA} must appear by itself on a single line, with no leading
61 whitespace and exactly one space between the words @code{END} and
62 @code{DATA}, followed immediately by the terminal dot, like this:
68 @node CLEAR TRANSFORMATIONS, DATA LIST, BEGIN DATA, Data Input and Output
69 @section CLEAR TRANSFORMATIONS
70 @vindex CLEAR TRANSFORMATIONS
73 CLEAR TRANSFORMATIONS.
76 @cmd{CLEAR TRANSFORMATIONS} clears out all pending
77 transformations. It does not cancel the current input program. It is
78 valid only when PSPP is interactive, not in syntax files.
80 @node DATA LIST, END CASE, CLEAR TRANSFORMATIONS, Data Input and Output
83 @cindex reading data from a file
84 @cindex data, reading from a file
85 @cindex data, embedding in syntax files
86 @cindex embedding data in syntax files
88 Used to read text or binary data, @cmd{DATA LIST} is the most
89 fundamental data-reading command. Even the more sophisticated input
90 methods use @cmd{DATA LIST} commands as a building block.
91 Understanding @cmd{DATA LIST} is important to understanding how to use
92 PSPP to read your data files.
94 There are two major variants of @cmd{DATA LIST}, which are fixed
95 format and free format. In addition, free format has a minor variant,
96 list format, which is discussed in terms of its differences from vanilla
99 Each form of @cmd{DATA LIST} is described in detail below.
102 * DATA LIST FIXED:: Fixed columnar locations for data.
103 * DATA LIST FREE:: Any spacing you like.
104 * DATA LIST LIST:: Each case must be on a single line.
107 @node DATA LIST FIXED, DATA LIST FREE, DATA LIST, DATA LIST
108 @subsection DATA LIST FIXED
109 @vindex DATA LIST FIXED
110 @cindex reading fixed-format data
111 @cindex fixed-format data, reading
112 @cindex data, fixed-format, reading
113 @cindex embedding fixed-format data
121 /[line_no] var_spec@dots{}
123 where each var_spec takes one of the forms
124 var_list start-end [type_spec]
125 var_list (fortran_spec)
128 @cmd{DATA LIST FIXED} is used to read data files that have values at fixed
129 positions on each line of single-line or multiline records. The
130 keyword FIXED is optional.
132 The FILE subcommand must be used if input is to be taken from an
133 external file. It may be used to specify a filename as a string or a
134 file handle (@pxref{FILE HANDLE}). If the FILE subcommand is not used,
135 then input is assumed to be specified within the command file using
136 @cmd{BEGIN DATA}@dots{}@cmd{END DATA} (@pxref{BEGIN DATA}).
138 The optional RECORDS subcommand, which takes a single integer as an
139 argument, is used to specify the number of lines per record. If RECORDS
140 is not specified, then the number of lines per record is calculated from
141 the list of variable specifications later in @cmd{DATA LIST}.
143 The END subcommand is only useful in conjunction with @cmd{INPUT
144 PROGRAM}. @xref{INPUT PROGRAM}, for details.
146 @cmd{DATA LIST} can optionally output a table describing how the data file
147 will be read. The TABLE subcommand enables this output, and NOTABLE
148 disables it. The default is to output the table.
150 The list of variables to be read from the data list must come last.
151 Each line in the data record is introduced by a slash (@samp{/}).
152 Optionally, a line number may follow the slash. Following, any number
153 of variable specifications may be present.
155 Each variable specification consists of a list of variable names
156 followed by a description of their location on the input line. Sets of
157 variables may specified using the @code{DATA LIST} TO convention
159 Variables}). There are two ways to specify the location of the variable
160 on the line: PSPP style and FORTRAN style.
162 With PSPP style, the starting column and ending column for the field
163 are specified after the variable name, separated by a dash (@samp{-}).
164 For instance, the third through fifth columns on a line would be
165 specified @samp{3-5}. By default, variables are considered to be in
166 @samp{F} format (@pxref{Input/Output Formats}). (This default can be
167 changed; see @ref{SET} for more information.)
169 When using PSPP style, to use a variable format other than the default,
170 specify the format type in parentheses after the column numbers. For
171 instance, for alphanumeric @samp{A} format, use @samp{(A)}.
173 In addition, implied decimal places can be specified in parentheses
174 after the column numbers. As an example, suppose that a data file has a
175 field in which the characters @samp{1234} should be interpreted as
176 having the value 12.34. Then this field has two implied decimal places,
177 and the corresponding specification would be @samp{(2)}. If a field
178 that has implied decimal places contains a decimal point, then the
179 implied decimal places are not applied.
181 Changing the variable format and adding implied decimal places can be
182 done together; for instance, @samp{(N,5)}.
184 When using PSPP style, the input and output width of each variable is
185 computed from the field width. The field width must be evenly divisible
186 into the number of variables specified.
188 FORTRAN style is an altogether different approach to specifying field
189 locations. With this approach, a list of variable input format
190 specifications, separated by commas, are placed after the variable names
191 inside parentheses. Each format specifier advances as many characters
192 into the input line as it uses.
194 In addition to the standard format specifiers (@pxref{Input/Output
195 Formats}), FORTRAN style defines some extensions:
199 Advance the current column on this line by one character position.
201 @item @code{T}@var{x}
202 Set the current column on this line to column @var{x}, with column
203 numbers considered to begin with 1 at the left margin.
205 @item @code{NEWREC}@var{x}
206 Skip forward @var{x} lines in the current record, resetting the active
207 column to the left margin.
210 Any format specifier may be preceded by a number. This causes the
211 action of that format specifier to be repeated the specified number of
214 @item (@var{spec1}, @dots{}, @var{specN})
215 Group the given specifiers together. This is most useful when preceded
216 by a repeat count. Groups may be nested arbitrarily.
219 FORTRAN and PSPP styles may be freely intermixed. PSPP style leaves the
220 active column immediately after the ending column specified. Record
221 motion using @code{NEWREC} in FORTRAN style also applies to later
222 FORTRAN and PSPP specifiers.
225 * DATA LIST FIXED Examples:: Examples of DATA LIST FIXED.
228 @node DATA LIST FIXED Examples, , DATA LIST FIXED, DATA LIST FIXED
229 @unnumberedsubsubsec Examples
234 DATA LIST TABLE /NAME 1-10 (A) INFO1 TO INFO3 12-17 (1).
243 Defines the following variables:
247 @code{NAME}, a 10-character-wide long string variable, in columns 1
251 @code{INFO1}, a numeric variable, in columns 12 through 13.
254 @code{INFO2}, a numeric variable, in columns 14 through 15.
257 @code{INFO3}, a numeric variable, in columns 16 through 17.
260 The @code{BEGIN DATA}/@code{END DATA} commands cause three cases to be
264 Case NAME INFO1 INFO2 INFO3
265 1 John Smith 10 23 11
266 2 Bob Arnold 12 20 15
270 The @code{TABLE} keyword causes PSPP to print out a table
271 describing the four variables defined.
275 DAT LIS FIL="survey.dat"
276 /ID 1-5 NAME 7-36 (A) SURNAME 38-67 (A) MINITIAL 69 (A)
281 Defines the following variables:
285 @code{ID}, a numeric variable, in columns 1-5 of the first record.
288 @code{NAME}, a 30-character long string variable, in columns 7-36 of the
292 @code{SURNAME}, a 30-character long string variable, in columns 38-67 of
296 @code{MINITIAL}, a 1-character short string variable, in column 69 of
300 Fifty variables @code{Q01}, @code{Q02}, @code{Q03}, @dots{}, @code{Q49},
301 @code{Q50}, all numeric, @code{Q01} in column 7, @code{Q02} in column 8,
302 @dots{}, @code{Q49} in column 55, @code{Q50} in column 56, all in the second
306 Cases are separated by a blank record.
308 Data is read from file @file{survey.dat} in the current directory.
310 This example shows keywords abbreviated to their first 3 letters.
314 @node DATA LIST FREE, DATA LIST LIST, DATA LIST FIXED, DATA LIST
315 @subsection DATA LIST FREE
316 @vindex DATA LIST FREE
320 [(@{TAB,'c'@}, @dots{})]
326 where each var_spec takes one of the forms
327 var_list [(type_spec)]
331 In free format, the input data is, by default, structured as a series
332 of fields separated by spaces, tabs, commas, or line breaks. Each
333 field's content may be unquoted, or it may be quoted with a pairs of
334 apostrophes (@samp{'}) or double quotes (@samp{"}). Unquoted white
335 space separates fields but is not part of any field. Any mix of
336 spaces, tabs, and line breaks is equivalent to a single space for the
337 purpose of separating fields, but consecutive commas will skip a
340 Alternatively, delimiters can be specified explicitly, as a
341 parenthesized, comma-separated list of single-character strings
342 immediately following FREE. The word TAB may also be used to specify
343 a tab character as a delimiter. When delimiters are specified
344 explicitly, only the given characters, plus line breaks, separate
345 fields. Furthermore, leading spaces at the beginnings of fields are
346 not trimmed, consecutive delimiters define empty fields, and no form
347 of quoting is allowed.
349 The NOTABLE and TABLE subcommands are as in @cmd{DATA LIST FIXED} above.
350 NOTABLE is the default.
352 The FILE and END subcommands are as in @cmd{DATA LIST FIXED} above.
354 The variables to be parsed are given as a single list of variable names.
355 This list must be introduced by a single slash (@samp{/}). The set of
356 variable names may contain format specifications in parentheses
357 (@pxref{Input/Output Formats}). Format specifications apply to all
358 variables back to the previous parenthesized format specification.
360 In addition, an asterisk may be used to indicate that all variables
361 preceding it are to have input/output format @samp{F8.0}.
363 Specified field widths are ignored on input, although all normal limits
364 on field width apply, but they are honored on output.
366 @node DATA LIST LIST, , DATA LIST FREE, DATA LIST
367 @subsection DATA LIST LIST
368 @vindex DATA LIST LIST
372 [(@{TAB,'c'@}, @dots{})]
378 where each var_spec takes one of the forms
379 var_list [(type_spec)]
383 With one exception, @cmd{DATA LIST LIST} is syntactically and
384 semantically equivalent to @cmd{DATA LIST FREE}. The exception is
385 that each input line is expected to correspond to exactly one input
386 record. If more or fewer fields are found on an input line than
387 expected, an appropriate diagnostic is issued.
389 @node END CASE, END FILE, DATA LIST, Data Input and Output
397 @cmd{END CASE} is used only within @cmd{INPUT PROGRAM} to output the
398 current case. @xref{INPUT PROGRAM}, for details.
400 @node END FILE, FILE HANDLE, END CASE, Data Input and Output
408 @cmd{END FILE} is used only within @cmd{INPUT PROGRAM} to terminate
409 the current input program. @xref{INPUT PROGRAM}.
411 @node FILE HANDLE, INPUT PROGRAM, END FILE, Data Input and Output
416 FILE HANDLE handle_name
418 /MODE=@{CHARACTER,IMAGE@}
423 Use @cmd{FILE HANDLE} to associate a file handle name with a file and
424 its attributes, so that later commands can refer to the file by its
425 handle name. Because names of text files can be specified directly on
426 commands that access files, @cmd{FILE HANDLE} is only needed when a
427 file is not an ordinary file containing lines of text. However,
428 @cmd{FILE HANDLE} may be used even for text files, and it may be
429 easier to specify a file's name once and later refer to it by an
432 Specify the file handle name as an identifier. Any given identifier may
433 only appear once in a PSPP run. File handles may not be reassigned to a
434 different file. The file handle name must immediately follow the @cmd{FILE
435 HANDLE} command name.
437 The NAME subcommand specifies the name of the file associated with the
438 handle. It is the only required subcommand.
440 MODE specifies a file mode. In CHARACTER mode, the default, the data
441 file is opened in ANSI C text mode, so that local end of line
442 conventions are followed, and each text line is read as one record.
443 In CHARACTER mode, most input programs will expand tabs to spaces
444 (@cmd{DATA LIST FREE} with explicitly specified delimiters is an
445 exception). By default, each tab is 4 characters wide, but an
446 alternate width may be specified on TABWIDTH. A tab width of 0
447 suppresses tab expansion entirely.
449 By contrast, in BINARY mode, the data file is opened in ANSI C binary
450 mode and records are a fixed length. In BINARY mode, LRECL specifies
451 the record length in bytes, with a default of 1024. Tab characters
452 are never expanded to spaces in binary mode.
454 @node INPUT PROGRAM, LIST, FILE HANDLE, Data Input and Output
455 @section INPUT PROGRAM
456 @vindex INPUT PROGRAM
460 @dots{} input commands @dots{}
464 @cmd{INPUT PROGRAM}@dots{}@cmd{END INPUT PROGRAM} specifies a
465 complex input program. By placing data input commands within @cmd{INPUT
466 PROGRAM}, PSPP programs can take advantage of more complex file
467 structures than available with only @cmd{DATA LIST}.
469 The first sort of extended input program is to simply put multiple @cmd{DATA
470 LIST} commands within the @cmd{INPUT PROGRAM}. This will cause all of
472 files to be read in parallel. Input will stop when end of file is
473 reached on any of the data files.
475 Transformations, such as conditional and looping constructs, can also be
476 included within @cmd{INPUT PROGRAM}. These can be used to combine input
477 from several data files in more complex ways. However, input will still
478 stop when end of file is reached on any of the data files.
480 To prevent @cmd{INPUT PROGRAM} from terminating at the first end of
482 the END subcommand on @cmd{DATA LIST}. This subcommand takes a
484 which should be a numeric scratch variable (@pxref{Scratch Variables}).
485 (It need not be a scratch variable but otherwise the results can be
486 surprising.) The value of this variable is set to 0 when reading the
487 data file, or 1 when end of file is encountered.
489 Two additional commands are useful in conjunction with @cmd{INPUT PROGRAM}.
490 @cmd{END CASE} is the first. Normally each loop through the
492 structure produces one case. @cmd{END CASE} controls exactly
493 when cases are output. When @cmd{END CASE} is used, looping from the end of
494 @cmd{INPUT PROGRAM} to the beginning does not cause a case to be output.
496 @cmd{END FILE} is the second. When the END subcommand is used on @cmd{DATA
497 LIST}, there is no way for the @cmd{INPUT PROGRAM} construct to stop
499 so an infinite loop results. @cmd{END FILE}, when executed,
500 stops the flow of input data and passes out of the @cmd{INPUT PROGRAM}
503 All this is very confusing. A few examples should help to clarify.
507 DATA LIST NOTABLE FILE='a.data'/X 1-10.
508 DATA LIST NOTABLE FILE='b.data'/Y 1-10.
513 The example above reads variable X from file @file{a.data} and variable
514 Y from file @file{b.data}. If one file is shorter than the other then
515 the extra data in the longer file is ignored.
522 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
525 DATA LIST NOTABLE END=#B FILE='b.data'/Y 1-10.
535 The above example reads variable X from @file{a.data} and variable Y from
536 @file{b.data}. If one file is shorter than the other then the missing
537 field is set to the system-missing value alongside the present value for
538 the remaining length of the longer file.
545 DATA LIST NOTABLE END=#B FILE='b.data'/X 1-10.
552 DATA LIST NOTABLE END=#A FILE='a.data'/X 1-10.
561 The above example reads data from file @file{a.data}, then from
562 @file{b.data}, and concatenates them into a single active file.
569 DATA LIST NOTABLE END=#EOF FILE='a.data'/X 1-10.
577 DATA LIST NOTABLE END=#EOF FILE='b.data'/X 1-10.
588 The above example does the same thing as the previous example, in a
594 COMPUTE X=UNIFORM(10).
599 LIST/FORMAT=NUMBERED.
602 The above example causes an active file to be created consisting of 50
603 random variates between 0 and 10.
605 @node LIST, MATRIX DATA, INPUT PROGRAM, Data Input and Output
612 /CASES=FROM start_index TO end_index BY incr_index
613 /FORMAT=@{UNNUMBERED,NUMBERED@} @{WRAP,SINGLE@}
617 The @cmd{LIST} procedure prints the values of specified variables to the
620 The VARIABLES subcommand specifies the variables whose values are to be
621 printed. Keyword VARIABLES is optional. If VARIABLES subcommand is not
622 specified then all variables in the active file are printed.
624 The CASES subcommand can be used to specify a subset of cases to be
625 printed. Specify FROM and the case number of the first case to print,
626 TO and the case number of the last case to print, and BY and the number
627 of cases to advance between printing cases, or any subset of those
628 settings. If CASES is not specified then all cases are printed.
630 The FORMAT subcommand can be used to change the output format. NUMBERED
631 will print case numbers along with each case; UNNUMBERED, the default,
632 causes the case numbers to be omitted. The WRAP and SINGLE settings are
633 currently not used. WEIGHT will cause case weights to be printed along
634 with variable values; NOWEIGHT, the default, causes case weights to be
635 omitted from the output.
637 Case numbers start from 1. They are counted after all transformations
638 have been considered.
640 @cmd{LIST} attempts to fit all the values on a single line. If needed
641 to make them fit, variable names are displayed vertically. If values
642 cannot fit on a single line, then a multi-line format will be used.
644 @cmd{LIST} is a procedure. It causes the data to be read.
646 @node MATRIX DATA, NEW FILE, LIST, Data Input and Output
654 /FORMAT=@{LIST,FREE@} @{LOWER,UPPER,FULL@} @{DIAGONAL,NODIAGONAL@}
655 /SPLIT=@{new_var,var_list@}
659 /CONTENTS=@{N_VECTOR,N_SCALAR,N_MATRIX,MEAN,STDDEV,COUNT,MSE,
660 DFE,MAT,COV,CORR,PROX@}
663 @cmd{MATRIX DATA} command reads square matrices in one of several textual
664 formats. @cmd{MATRIX DATA} clears the dictionary and replaces it and
668 Use VARIABLES to specify the variables that form the rows and columns of
669 the matrices. You may not specify a variable named @code{VARNAME_}. You
670 should specify VARIABLES first.
672 Specify the file to read on FILE, either as a file name string or a file
673 handle (@pxref{FILE HANDLE}). If FILE is not specified then matrix data
674 must immediately follow @cmd{MATRIX DATA} with a @cmd{BEGIN
675 DATA}@dots{}@cmd{END DATA}
676 construct (@pxref{BEGIN DATA}).
678 The FORMAT subcommand specifies how the matrices are formatted. LIST,
679 the default, indicates that there is one line per row of matrix data;
680 FREE allows single matrix rows to be broken across multiple lines. This
681 is analogous to the difference between @cmd{DATA LIST FREE} and
683 (@pxref{DATA LIST}). LOWER, the default, indicates that the lower
684 triangle of the matrix is given; UPPER indicates the upper triangle; and
685 FULL indicates that the entire matrix is given. DIAGONAL, the default,
686 indicates that the diagonal is part of the data; NODIAGONAL indicates
687 that it is omitted. DIAGONAL/NODIAGONAL have no effect when FULL is
690 The SPLIT subcommand is used to specify @cmd{SPLIT FILE} variables for the
691 input matrices (@pxref{SPLIT FILE}). Specify either a single variable
692 not specified on VARIABLES, or one or more variables that are specified
693 on VARIABLES. In the former case, the SPLIT values are not present in
694 the data and ROWTYPE_ may not be specified on VARIABLES. In the latter
695 case, the SPLIT values are present in the data.
697 Specify a list of factor variables on FACTORS. Factor variables must
698 also be listed on VARIABLES. Factor variables are used when there are
699 some variables where, for each possible combination of their values,
700 statistics on the matrix variables are included in the data.
702 If FACTORS is specified and ROWTYPE_ is not specified on VARIABLES, the
703 CELLS subcommand is required. Specify the number of factor variable
704 combinations that are given. For instance, if factor variable A has 2
705 values and factor variable B has 3 values, specify 6.
707 The N subcommand specifies a population number of observations. When N
708 is specified, one N record is output for each @cmd{SPLIT FILE}.
710 Use CONTENTS to specify what sort of information the matrices include.
711 Each possible option is described in more detail below. When ROWTYPE_
712 is specified on VARIABLES, CONTENTS is optional; otherwise, if CONTENTS
713 is not specified then /CONTENTS=CORR is assumed.
718 Number of observations as a vector, one value for each variable.
720 Number of observations as a single value.
726 Vector of standard deviations.
730 Vector of mean squared errors.
732 Vector of degrees of freedom.
743 The exact semantics of the matrices read by @cmd{MATRIX DATA} are complex.
744 Right now @cmd{MATRIX DATA} isn't too useful due to a lack of procedures
745 accepting or producing related data, so these semantics aren't
746 documented. Later, they'll be described here in detail.
748 @node NEW FILE, PRINT, MATRIX DATA, Data Input and Output
756 @cmd{NEW FILE} command clears the current active file.
758 @node PRINT, PRINT EJECT, NEW FILE, Data Input and Output
767 /[line_no] arg@dots{}
769 arg takes one of the following forms:
771 var_list start-end [type_spec]
772 var_list (fortran_spec)
776 The @cmd{PRINT} transformation writes variable data to an output file.
777 @cmd{PRINT} is executed when a procedure causes the data to be read.
778 Follow @cmd{PRINT} by @cmd{EXECUTE} to print variable data without
779 invoking a procedure (@pxref{EXECUTE}).
781 All @cmd{PRINT} subcommands are optional.
783 The OUTFILE subcommand specifies the file to receive the output. The
784 file may be a file name as a string or a file handle (@pxref{FILE
785 HANDLE}). If OUTFILE is not present then output will be sent to PSPP's
788 The RECORDS subcommand specifies the number of lines to be output. The
789 number of lines may optionally be surrounded by parentheses.
791 TABLE will cause the PRINT command to output a table to the listing file
792 that describes what it will print to the output file. NOTABLE, the
793 default, suppresses this output table.
795 Introduce the strings and variables to be printed with a slash
796 (@samp{/}). Optionally, the slash may be followed by a number
797 indicating which output line will be specified. In the absence of this
798 line number, the next line number will be specified. Multiple lines may
799 be specified using multiple slashes with the intended output for a line
800 following its respective slash.
802 Literal strings may be printed. Specify the string itself. Optionally
803 the string may be followed by a column number or range of column
804 numbers, specifying the location on the line for the string to be
805 printed. Otherwise, the string will be printed at the current position
808 Variables to be printed can be specified in the same ways as available
809 for @cmd{DATA LIST FIXED} (@pxref{DATA LIST FIXED}). In addition, a
811 list may be followed by an asterisk (@samp{*}), which indicates that the
812 variables should be printed in their dictionary print formats, separated
813 by spaces. A variable list followed by a slash or the end of command
814 will be interpreted the same way.
816 If a FORTRAN type specification is used to move backwards on the current
817 line, then text is written at that point on the line, the line will be
818 truncated to that length, although additional text being added will
819 again extend the line to that length.
821 @node PRINT EJECT, PRINT SPACE, PRINT, Data Input and Output
830 /[line_no] arg@dots{}
832 arg takes one of the following forms:
834 var_list start-end [type_spec]
835 var_list (fortran_spec)
839 @cmd{PRINT EJECT} writes data to an output file. Before the data is
840 written, the current page in the listing file is ejected.
842 @xref{PRINT}, for more information on syntax and usage.
844 @node PRINT SPACE, REREAD, PRINT EJECT, Data Input and Output
849 PRINT SPACE OUTFILE='filename' n_lines.
852 @cmd{PRINT SPACE} prints one or more blank lines to an output file.
854 The OUTFILE subcommand is optional. It may be used to direct output to
855 a file specified by file name as a string or file handle (@pxref{FILE
856 HANDLE}). If OUTFILE is not specified then output will be directed to
859 n_lines is also optional. If present, it is an expression
860 (@pxref{Expressions}) specifying the number of blank lines to be
861 printed. The expression must evaluate to a nonnegative value.
863 @node REREAD, REPEATING DATA, PRINT SPACE, Data Input and Output
868 REREAD FILE=handle COLUMN=column.
871 The @cmd{REREAD} transformation allows the previous input line in a
873 already processed by @cmd{DATA LIST} or another input command to be re-read
874 for further processing.
876 The FILE subcommand, which is optional, is used to specify the file to
877 have its line re-read. The file must be specified in the form of a file
878 handle (@pxref{FILE HANDLE}). If FILE is not specified then the last
879 file specified on @cmd{DATA LIST} will be assumed (last file specified
880 lexically, not in terms of flow-of-control).
882 By default, the line re-read is re-read in its entirety. With the
883 COLUMN subcommand, a prefix of the line can be exempted from
884 re-reading. Specify an expression (@pxref{Expressions}) evaluating to
885 the first column that should be included in the re-read line. Columns
886 are numbered from 1 at the left margin.
888 Issuing @code{REREAD} multiple times will not back up in the data
889 file. Instead, it will re-read the same line multiple times.
891 @node REPEATING DATA, WRITE, REREAD, Data Input and Output
892 @section REPEATING DATA
893 @vindex REPEATING DATA
901 /CONTINUED[=cont_start-cont_end]
902 /ID=id_start-id_end=id_var
904 /DATA=var_spec@dots{}
906 where each var_spec takes one of the forms
907 var_list start-end [type_spec]
908 var_list (fortran_spec)
911 @cmd{REPEATING DATA} parses groups of data repeating in
912 a uniform format, possibly with several groups on a single line. Each
913 group of data corresponds with one case. @cmd{REPEATING DATA} may only be
914 used within an @cmd{INPUT PROGRAM} structure (@pxref{INPUT PROGRAM}).
915 When used with @cmd{DATA LIST}, it
916 can be used to parse groups of cases that share a subset of variables
917 but differ in their other data.
919 The STARTS subcommand is required. Specify a range of columns, using
920 literal numbers or numeric variable names. This range specifies the
921 columns on the first line that are used to contain groups of data. The
922 ending column is optional. If it is not specified, then the record
923 width of the input file is used. For the inline file (@pxref{BEGIN
924 DATA}) this is 80 columns; for a file with fixed record widths it is the
925 record width; for other files it is 1024 characters by default.
927 The OCCURS subcommand is required. It must be a number or the name of a
928 numeric variable. Its value is the number of groups present in the
931 The DATA subcommand is required. It must be the last subcommand
932 specified. It is used to specify the data present within each repeating
933 group. Column numbers are specified relative to the beginning of a
934 group at column 1. Data is specified in the same way as with @cmd{DATA LIST
935 FIXED} (@pxref{DATA LIST FIXED}).
937 All other subcommands are optional.
939 FILE specifies the file to read, either a file name as a string or a
940 file handle (@pxref{FILE HANDLE}). If FILE is not present then the
941 default is the last file handle used on @cmd{DATA LIST} (lexically, not in
942 terms of flow of control).
944 By default @cmd{REPEATING DATA} will output a table describing how it will
945 parse the input data. Specifying NOTABLE will disable this behavior;
946 specifying TABLE will explicitly enable it.
948 The LENGTH subcommand specifies the length in characters of each group.
949 If it is not present then length is inferred from the DATA subcommand.
950 LENGTH can be a number or a variable name.
952 Normally all the data groups are expected to be present on a single
953 line. Use the CONTINUED command to indicate that data can be continued
954 onto additional lines. If data on continuation lines starts at the left
955 margin and continues through the entire field width, no column
956 specifications are necessary on CONTINUED. Otherwise, specify the
957 possible range of columns in the same way as on STARTS.
959 When data groups are continued from line to line, it is easy
960 for cases to get out of sync through careless hand editing. The
961 ID subcommand allows a case identifier to be present on each line of
962 repeating data groups. @cmd{REPEATING DATA} will check for the same
963 identifier on each line and report mismatches. Specify the range of
964 columns that the identifier will occupy, followed by an equals sign
965 (@samp{=}) and the identifier variable name. The variable must already
966 have been declared with @cmd{NUMERIC} or another command.
968 @cmd{REPEATING DATA} should be the last command given within an
969 @cmd{INPUT PROGRAM}. It should not be enclosed within a @cmd{LOOP}
970 structure (@pxref{LOOP}). Use @cmd{DATA LIST} before, not after,
971 @cmd{REPEATING DATA}.
973 @node WRITE, , REPEATING DATA, Data Input and Output
982 /[line_no] arg@dots{}
984 arg takes one of the following forms:
986 var_list start-end [type_spec]
987 var_list (fortran_spec)
991 @code{WRITE} writes text or binary data to an output file.
993 @xref{PRINT}, for more information on syntax and usage. The main
994 difference between @code{PRINT} and @code{WRITE} is that @cmd{WRITE}
995 uses write formats by default, where PRINT uses print formats.
997 The sole additional difference is that if @cmd{WRITE} is used to send output
998 to a binary file, carriage control characters will not be output.
999 @xref{FILE HANDLE}, for information on how to declare a file as binary.
1000 @setfilename ignored