Welcome to the Computational Thinking using Julia for Real-World Problems at MIT!
The aim of this course is to bring together concepts from computer science and applied math with coding in the modern Julia language, and to see how to apply these techniques to study interesting applications (and of course to have fun).
We would be pleased if students who have been interested in computer science now become interested in computational science and those interested in scientific applications learn computer science they may not see elsewhere. ... and for all students, we wish to share the value of the Julia language as the best of both worlds.
Applications of computer science in the real world use data, i.e. information that we can measure in some way. Data take many different forms, for example:
Now suppose that we want to examine a piece of the image in more detail. We need some way of specifying which piece of the image we want.
Thinking of the image as a grid of pixels, we need a way to tell the computer which pixel or group of pixels we want to refer to. Since the image is a two-dimensional grid, we can use two integers (whole numbers) to give the coordinates of a single pixel. Specifying coordinates like this is called indexing: think of the index of a book, which tells you on which page an idea is discussed.
In Julia we use (square) brackets, [ and ] for indexing: