Writing out data in a user-defined format

The format in which the data is to be written and the data types of the variables used. The format string consists of optional text interspersed with references to variables in the list:

Print an integer variable in the next num_pos positions on the line. If the variable has a negative value the value is printed starting with a minus sign.

Print a real variable in the next num_pos positions on the line and with dec_pl decimal places. The number of print positions must allow for the required number of decimal places and a decimal point.

Print num_col columns starting with the column whose name or number appears in the variable list. Columns are printed as texts not punch codes; that is, multicodes are converted to letters where possible.

A comma-separated list of the variables to be written out. Variables must be listed in the order they are used in the format statement.

write and report are both powerful statements for writing out data, but they do have limitations which you might find restrictive in some circumstances. The write statement lets you write data out to a print file, including the standard print file (usually called out2), but it always writes the data in a fixed format that you cannot change. The report statement lets you write out data and text in any format you like, but only to a report file. You cannot write to a print file with report.

The qfprnt function brings together the functionality of write and report by writing text and data to the standard print file in a format of your choice.

If the respondent tested five products this statement will appear in the standard print file as:

The underscore character in front of the 5 represents a space and appears as such in the print file.

The format section of the statement consists of text to be printed exactly as it is written and references to variables whose values are to be substituted in the text at the given points. This example writes out the value of the numeric (integer) variable t1. The variable is named in the variable list section of the statement and is represented by the characters %2i in the format section.

There are three parts to the variable’s reference. The % sign signals to Quantum that it has reached a variable reference: all references start with %. The i says that the variable is an integer variable and the 2 says how many print positions to reserve for printing this variable. In the example two positions are reserved for printing the value of t1, but since the value of t1 is only 5, Quantum prints the value on the right of the reserved space and fills the remaining positions with spaces. The sample output uses an underscore to represent this space.

Here is another example using two integer variables:

This produces lines of the form:

The underscore represents a space used to pad a value to the full field width.

This qfprnt statement produces the correct results because the variables are in the same order as their references in the format section. This is your responsibility. As long as a variable has the same type as the reference in the corresponding position in the format section, Quantum prints its value at that point in the statement. So, if you write:

Quantum does not increase the number of print positions to accommodate the value it needs to print. Instead, it prints asterisks. In this example, the asterisks alert you to the fact that there is something wrong with the qfprnt specification, but this would not always be so.

If Quantum needs to print a negative number, it prints the minus sign directly in front of the first digit, just as you would write it manually.

To print a real variable, type:

num_pos is the number of print positions required. dec_pl is the number of decimal places. As an example, the statement:

prints the value of the real variable called liters in a field 5 positions wide. The value is printed with two decimal places so, allowing for the decimal point, the maximum value that can be printed in 99.99:

Quantum can also print the text values of a column, a field of columns or a data variable. This means that Quantum converts multicodes to letters or other keyboard characters before printing them. Multicodes that do not correspond to letters or characters are printed as asterisks. For example, the multicode ‘&1’ translates into the letter A and would be printed as such; the multicode ‘&123’ is simply as collection of codes and would therefore be printed as an asterisk.

To print single columns, type:

in the format section, where number is the number of print positions required, and the name of a single column in the corresponding position in the variable list. Quantum will then print number columns starting at the named column. For example: