Defining single observations

 

Syntax

1. BD>data : D(I)=E

2. BD>data : D(E )=E

where is the name of a data-carrier, is a valid equation (optionally excluding parentheses), is a valid equation which should round to a positive integer (the rounding is performed by the program), and is a positive integer.

In addition to reading lists of data for collections of quantities, the DATA:  command can also be used to define one-off observations. Here, is the name of some data-element or element (the data-element will be constructed if it does not exist already), is the case being defined, and the result of the equation will be assigned as the observation. For example, the following fragment of code

BD>data : pressure(3)=50.7

makes the third observation on the data-carrier ``pressure'' equal to 50.7. The first form of the syntax is the most commonly used. The second form of the syntax allows the case number to be defined as an equation: the following two lines of code are equivalent:

1. BD>c : %t=1

   BD>data : x((%t+3))=5

2. BD>data : x(4)=5