THE VAL_ FUNCTIONS

The VAL_ functions are a set of Fortran functions which perform arithmetic, mathematical operations and type conversion on single (scalar) values stored using any numerical data type. These functions will handle numerical errors which occur during their evaluation (such as division by zero or overflow) and can also recognise and propagate the standard Starlink bad values.

They are normally invoked by statements of the form:

	RESULT = VAL_$<$name$>$( BAD, ARG, STATUS )
or	RESULT = VAL_$<$name$>$( BAD, ARG1, ARG2, STATUS )

where $<$name$>$ specifies the operation to be performed and:

• BAD is a logical value specifying whether bad input arguments are to be recognised;

• ARG, ARG1 and ARG2 are the input arguments;

• STATUS is an integer error status variable.