1) classic Fortran 77 style.#include "petsc-finclude/petscXXX.h" to work with material from the XXX component of PETSc
You cannot use this approach if you wish to use the Fortran 90 specific PETSc routines
which end in F90; such as VecGetArrayF90()
2) classic Fortran 90 style.#include "petsc-finclude/petscXXX.h" .#include "petsc-finclude/petscXXX.h90" to work with material from the XXX component of PETSc
3) Using Fortran modules.#include "petsc-finclude/petscXXXdef.h"
4) Use Fortran modules and Fortran data types for PETSc types.#include "petsc-finclude/petscXXXdef.h"
To use this approach you must ./configure PETSc with the additional
option --with-fortran-datatypes You cannot use the type(XXX) declaration approach without using Fortran modules
Finally if you absolutely do not want to use any #include you can use either
3a) skip the #include BUT you cannot use any PETSc data type names like Vec, Mat, PetscInt, PetscErrorCode etc
and you must declare the variables as integer, for example
4a) skip the #include, you use the object types like type(Vec) type(Mat) but cannot use the data type
names like PetscErrorCode, PetscInt etc. again for those you must use integer
We recommend either 2 or 3. Approaches 2 and 3 provide type checking for most PETSc function calls; 4 has type checking for only a few PETSc functions.
Fortran type checking with interfaces is strick, this means you cannot pass a scalar value when an array value is expected (even though it is legal Fortran). For example when setting a single value in a matrix with MatSetValues() you cannot have something like
call MatSetValues(mat,1,row,1,col,val,INSERT_VALUES,ierr)You must instead have
See the example src/vec/vec/examples/tutorials/ex20f90.F90 for an example that can use all four approaches
Developer Notes: The petsc-finclude/petscXXXdef.h contain all the #defines (would be typedefs in C code) these automatically include their predecessors; for example petsc-finclude/petscvecdef.h includes petsc-finclude/petscisdef.h
The petsc-finclude/petscXXXX.h contain all the parameter statements for that package. These automatically include their petsc-finclude/petscXXXdef.h file but DO NOT automatically include their predecessors; for example petsc-finclude/petscvec.h does NOT automatically include petsc-finclude/petscis.h
The petsc-finclude/ftn-custom/petscXXXdef.h90 are not intended to be used directly in code, they define the Fortran data type type(XXX) (for example type(Vec)) when PETSc is ./configure with the --with-fortran-datatypes option.
The petsc-finclude/ftn-custom/petscXXX.h90 (not included directly by code) contain interface definitions for the PETSc Fortran stubs that have different bindings then their C version (for example VecGetArrayF90).
The petsc-finclude/ftn-auto/petscXXX.h90 (not included directly by code) contain interface definitions generated automatically by "make allfortranstubs".
The petsc-finclude/petscXXX.h90 includes the custom petsc-finclude/ftn-custom/petscXXX.h90 and if ./configure was run with --with-fortran-interfaces it also includes the petsc-finclude/ftn-auto/petscXXX.h90 These DO NOT automatically include their predecessors
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages src/vec/vec/examples/tutorials/ex20f90.F90.html