Fortran (a contraction of Formula Translation) was the first programming language to have a standard (in 1954), but has changed significantly over the years. More recent standards (the latest being Fortran 2018) come under the umbrella term "Modern Fortran". Fortran retains very great significance in many areas of scientific and numerical computing, particularly for applications such as quantum chemistry, plasmas, engineering and fluid dynamics, and in numerical weather prediction and climate models.
This intermediate course concentrates on some of the more recent features which are central to Modern Fortran. Attendees should be familiar with the basics of Fortran programming which might be covered in an introductory course, e.g., the one at,
https://github.com/ARCHER2-HPC/archer2-fortran-intro
So, attendees should be comfortable writing structured Fortran programs based on modules and procedures, and have a sound grounding in variables, logic, flow-of-control, and so on. Some knowledge of Fortran I/O is assumed.
There are two main topics in this intermediate course: the facilities in
Fortran for abstraction and polymorphism provided by classes and
interfaces, and the facilities for formal
interoperability with ANSI C. The course will cover type extension
("classes" and "inheritance"), type-bound procedures ("methods"),
generic procedures ("polymorphism"), and so on. The standard iso_c_binding
module provides facilities for interoperability with C; this allow the
communication of Fortran entities with direct analogues C, and also Fortran
objects (particularly arrays) which have no direct analogue in C.
Further language features concerning arrays, pointers, and facilities for structured programming using submodules will also be covered along the way.
Knowledge of the object-oriented paradigm would be useful, but is not essential. Knowledge of C is required for the material on C/Fortran interoperation. The course will allow programmers interested in working on larger, structured, software projects to make use of (almost) a full complement of Modern Fortran features.
The course requires a Fortran compiler, for which a local machine or laptop may be appropriate [1]. If you do not have access to a Fortran compiler, course training accounts on ARCHER2 will be available which provide access to various compilers. Use of a text editor will be required (some may prefer an IDE, but we do not intend to consider or support IDEs).
[1] This may typically be gfortran, freely available as part of the
GNU Compiler Collection (GCC).
See e.g., https://gcc.gnu.org/wiki/GFortranBinaries
For details of how to log into an ARCHER2 account, see the ARCHER2 Quickstart for users.
Check out the git repository to your laptop or ARCHER2 account.
$ git clone https://github.com/ARCHER2-HPC/archer2-fortran-inter.gitThe default Fortran compiler on ARCHER2 is the Cray Fortran compiler invoked using ftn.
For example,
$ cd section-1.01
$ ftn example1.f90should generate an executable with the default name a.out.
Each section of the course is associated with a different directory, each of which contains a number of example programs and exercise templates. Answers to exercises generally re-appear as templates to later exercises. Miscellaneous solutions also appear in the solutions directory.
Not all the examples compile. Some have deliberate errors which will be discussed as part of the course.
This is a two-day course.
| Time | Content | Section |
|---|---|---|
| 09:30 | Logistics: login, compiler set-up, local details | None |
| See above | ||
| 10:00 | Arrays: recap | |
declarations, sections, constructors, allocatable |
section-1.01 | |
| 10:20 | Arrays as arguments | |
| assumed shape, restrictions on arguments, ... | section-1.02 | |
| 10:40 | Pointers and procedures | |
pointer, target, contiguous, procedure pointers |
section-1.03 | |
| 11:00 | Break | |
| 11:30 | Derived types | |
type, components, assignments and copying |
section-2.01 | |
| 11:50 | Interfaces and generic procedures | |
interface, operator |
section-2.02 | |
| 12:20 | Type extension and polymorphism | |
type, extends(...), class |
section-2.03 | |
| 12:40 | Type-bound procedures | |
contains procedure, pass, generic |
section-2.04 | |
| 13:00 | Lunch | |
| 14:00 | Input/output for types | |
write(formatted) |
section-3.01 | |
| 15:00 | Break | |
| 15:30 | Interfaces and abstract types | |
type, abstract, deferred |
section-4.01 | |
| 17:00 | Close |
| Time | Content | Section |
|---|---|---|
| 09:30 | Submodules | |
module, submodule |
section-5.01 | |
| 10:10 | Unlimited polymorphic entities | |
class (*), typed allocations |
section-5.02 | |
| 11:00 | Break | |
| 11:30 | Type parameters | section-6.01 |
kind, len |
||
| 11:50 | Intrinsic modules | |
iso_fortran_env, ieee_exceptions, ieee_arithmetic |
section-6.02 | |
| 12:10 | Interoperability with C | |
iso_c_binding |
section-6.03 | |
| 13:00 | Lunch | |
| 14:00 | ... | |
| 15:00 | Break | |
| 15:20 | Exercises | |
| 15:50 | Closing statements | |
| 16:00 | Close |
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