Operations on functions will be executed only if the corresponding x-ranges have been defined correctly. For routines needing several functions it is not assumed that they are defined at the same points. So it is necessary to be able to evaluate the functions at any point. As indicated in 3.1 this is done as follows : the functions are supposed to be linear between two successive points where they are defined, and are constant before the first point and after the last point. The following operations of functions are implemented :
- Evaluation
- Addition
- Substraction
- Multiplication
- Composition
- Convolution
- Copy
- Differentiation
- Integration
- Inversion
- Real and imaginary parts of complex functions
Several commands are available to set the values of functions and x-ranges. In particular it is possible to fill functions with data contained in files. The list of all commands of funct dealing with functions is given in 3.4.
There are no commands to convert simple precision functions into double precision ones or conversely. So it is better to use the same precision for all functions.
Two tranforms are implemented : Fourier and Bessel transforms (cf. 3.3).