How to Learn to Code in Fortran

Hey, are you interested in coding for science? Fortran's your guy! It's been around for ages, but it's still super strong for doing really complex math problems. They use it in physics, engineering, even predicting the weather!

Why Learn Fortran?

You might be thinking, "There are so many new languages, why Fortran?" Good question. Here's why it's still awesome:

• It's fast! If you're doing a ton of calculations, Fortran is like a race car. It gets the job done quickly.
• A lot of old code uses Fortran. If you want to work with existing scientific programs, you'll need to know Fortran. It's like the old language of science, but still really useful.
• It has amazing tools for math. Fortran has special libraries, like LAPACK and BLAS. Think of them like super-powered calculators for advanced math problems.
• There's a whole group of Fortran people! You won't be alone! There are tons of programmers who can help you if you get stuck.

Getting Started with Fortran

First, you need a special program called a compiler. Think of it like a translator that turns your code into something the computer can understand. Here are a few popular ones:

• gfortran: This one is free and comes with a bunch of other tools.
• Intel Fortran Compiler: This one is made for serious work and is really good at making your code run super fast.
• IBM XL Fortran: This one is built specifically for computers from IBM.

Once you have your compiler, you can start writing your first program! Use a text editor to write your code, and save it with the .f90 or .f95 extension. To run your program, you'll type some commands in your terminal. It looks like this:

bash gfortran your_program.f90 -o your_program ./your_program

The Basics of Fortran

Let's talk about some of the building blocks of Fortran:

1. Variables

Variables are like containers that hold information in your program. To create a variable in Fortran, you tell it what kind of data it will hold and give it a name. Here's an example:

fortran integer :: age real :: weight character(len=20) :: name

Here, we created three variables: age holds whole numbers (integers) weight holds numbers with decimal points (real numbers) name holds a string of characters (like your name). It can hold up to 20 characters!

2. Operators

Operators are like little symbols that tell Fortran to do things with your data. Here are a few common ones:

• Arithmetic Operators: +, -, , /, *(for exponents). These are like the symbols you use in math class.
• Logical Operators: .eq. (equals), .ne. (not equals), .lt. (less than), .gt. (greater than), .le. (less than or equal to), .ge. (greater than or equal to), .and. (and), .or. (or), .not. (not). These let you compare things and make decisions in your code.

3. Control Flow

Control flow tells Fortran what order to do things. It's like giving your program instructions.

• if-then-else: You can use this to make your program choose what to do based on whether something is true or false. Imagine you're making a game, and you want a character to jump if they press a button. You would use an "if-then-else" statement to check if the button was pressed, and if it was, make the character jump.
• do loop: This lets you repeat a section of code over and over again. It's like saying, "Do this thing 10 times." Imagine you have a list of names, and you want to print each name. You could use a "do loop" to go through the list and print each name one at a time.
• select case: This lets you choose what to do based on the value of something. Imagine you have a quiz, and you want to give different feedback based on the score. You could use a "select case" to check the score and give the appropriate feedback.

Example Program: Calculating the Area of a Circle

Let's try a simple program: It calculates the area of a circle.

fortran program circle_area implicit none real :: radius, area real, parameter :: pi = 3.14159 ! Get the radius from the user write(,) 'Enter the radius of the circle:' read(,) radius ! Calculate the area area = pi radius*2 ! Display the result write(,) 'The area of the circle is:', area end program circle_area

This program does the following:

1. It creates variables called "radius" and "area" to hold the information we need. It also sets the value of "pi" to a very precise number.
2. It asks the user to type in the radius of the circle.
3. It calculates the area using the formula "area = pi radius squared".
4. It prints out the area of the circle.

Where Can You Use Fortran?

Fortran is super powerful for science and engineering problems! Here are a few areas where it's commonly used:

• Supercomputers: Fortran is used to simulate really big things, like weather patterns, how fluids move, or the behavior of tiny particles in physics.
• Science Research: Scientists use Fortran to create models and analyze data in astronomy, chemistry, and materials science. It's like a secret weapon for solving scientific mysteries!
• Engineering: Engineers use Fortran to design buildings, optimize systems, and control robots. It's essential for building things that are safe and work perfectly.
• Finance: Even the world of money uses Fortran! They use it for managing risk, investing money, and figuring out the value of complicated financial products.

Beyond the Basics

Once you've mastered the basics, Fortran has a whole bunch of advanced features to explore.

• Arrays: Arrays are like lists of numbers. Imagine you're organizing the scores of all the students in your class. You could use an array to store all those scores in one place.
• Modules: Modules are like special containers that let you organize your code in a neat way. It's like having folders for all your files, but for code!
• Pointers: Pointers are a little tricky, but they let your code access the computer's memory directly. This can be super helpful for making your code run really fast.
• Object-Oriented Programming (OOP): OOP is a way to write code that's more organized and reusable. Think of it like having building blocks that you can use to create different programs easily.

How to Learn More

Ready to get started? Here are a few ways to learn Fortran:

• Online Tutorials: Sites like W3Schools, Tutorialspoint, and Learn Fortran have interactive lessons and practice problems.
• Books: There are books on Fortran for every level, like "Fortran 90/95 Explained" by Metcalf and Reid.
• Fortran Forums: You can ask questions and share knowledge with other Fortran programmers online.

Conclusion

Fortran is a powerful language with a long history and a bright future in science and engineering. It's a great tool for tackling complex math problems and unlocking the secrets of the universe! So go ahead and explore this amazing language!