16.4.8 The READ and WRITE Commands

The READ and WRITE commands perform matrix input and output with text files. They share the following syntax for specifying how data is divided among input lines:

/FIELD=_first_ TO _last_ [BY _width_]
[/FORMAT=_format_]

Both commands require the FIELD subcommand. It specifies the range of columns, from first to last, inclusive, that the data occupies on each line of the file. The leftmost column is column 1. The columns must be literal numbers, not expressions. To use entire lines, even if they might be very long, specify a column range such as 1 TO 100000.

The FORMAT subcommand is optional for numerical matrices. For string matrix input and output, specify an A format. In addition to FORMAT, the optional BY specification on FIELD determine the meaning of each text line:

• With neither BY nor FORMAT, the numbers in the text file are in F format separated by spaces or commas. For WRITE, PSPP uses as many digits of precision as needed to accurately represent the numbers in the matrix.
• BY _width_ divides the input area into fixed-width fields with the given width. The input area must be a multiple of width columns wide. Numbers are read or written as F _width_.0 format.
• FORMAT="_count_ F" divides the input area into integer count equal-width fields per line. The input area must be a multiple of count columns wide. Another format type may be substituted for F.
• FORMAT=F _w_[._d_] divides the input area into fixed-width fields with width w. The input area must be a multiple of w columns wide. Another format type may be substituted for F. The READ command disregards d.
• FORMAT=F specifies format F without indicating a field width. Another format type may be substituted for F. The WRITE command accepts this form, but it has no effect unless BY is also used to specify a field width.

If BY and FORMAT both specify or imply a field width, then they must indicate the same field width.

• The READ Command
• The WRITE Command