To get EASISTAT to do anything you have to give it a command to perform. Most commands will also require other information, such as which columns to apply a particular analysis to. The way in which this information is specified can be called the format or syntax of the command. When each command is described in this manual its format is defined with it, but to understand the format required there are some important general rules it is helpful to become familiar with first.
To illustrate these rules we will take the SUMMARY command, which is described later in the manual in the following way:
Format: S[ummary] [r[anks]] column [if condition]This means that the command is called SUMMARY, but that all but the first letter S is optional, that it can have an optional switch called RANKS, that the column to be studied must be specified, and that finally one can add logical and arithmetic conditions limiting the rows to be studied by entering IF followed by a condition. This means that one can enter for instance:
SUMMARY RANKS C1 IF (C2-C3)<7This command would cause the basic description of the values in column 1 to be displayed (their mean, mode, standard deviation, etc.), taking only those rows for which the value in column 2 minus the value in column 3 was less than 7, and would also display the rank and frequency table of the values. In the sections which follow we will look at the individual aspects of command format more closely.
Entering a command
Command options
Referring to entries in the data table
Logical expressions
Arithmetic expressions
Operator precedence
Combining arithmetic and logical operations
General purpose variables
Rules for label names