Introduction

The source code of Afivo is located in different folders:

Folder	Description
src	Contains the source code of the framework
examples	Contains example programs
documentation	Contains the Doxygen documentation
tests	Contains tests of the framework
`external_libraries`	Contains required external libraries
`lib_2d` and `lib_3d`	The Afivo library in 2D/3D

The src folder

The folder src contains the source of Afivo, split over several modules (see the Modules page). These modules contain the code for both 2D and 3D functionality. The translation is performed using a couple simple preprocessor rules:

Pattern	Replacement 2D	Replacement 3D
`NDIM`	2	3
`IJK`	`i, j`	`i, j, k`

To simplify writing loops, a few patterns are defined in cpp_macros_2d.h and cpp_macros_3d.h:

do KJI_DO(a,b)
--->
2D: do j = a, b; do i = a, b
3D: do k = a, b; do j = a, b; do i = a, b

end do; CLOSE_DO
--->
2D: end do; end do
3D: end do; end do; end do

DTIMES(xx)
--->
2D: xx, xx
3D: xx, xx, xx

Blocks of code specific for 2D and 3D can be written as:

#if NDIM == 2
    ...
#elif NDIM == 3
    ...
#endif