You can specify expressions for the x and y axes, where each expression is a standard algebraic expression which can contain parameters of the database, numeric constants, and commonly used functions. See appendix B for a list of math functions and operators that can be used in the expressions. For example, TE*NE/PB, 2+LOG(PB), and 1-BETA are valid expressions, where TE, NE, PB, and BETA are names of parameters or expressions defined in the database. If the value of a parameter in an expression is NODATA null , then that record will not be plotted. RETURN at the expression prompts will show a list of all parameters. If you use blanks in an expression, it must be enclosed in double quotes, e.g., "A * B". Note: Integer ratios are truncated in expression evaluation. If you ask for 20/100 to be retrieved the result is 0; if you ask for 20./100 the result is 0.2. To store frequently used expressions in the database see section 4.2.