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I’m very, very slowly working my way through the first of Andrej Karpathy’s “Neural Networks: Zero to Hero” video series as part of one of my missions this year — to pick up some AI programming skills.

I’m deliberately moving very, very, slowly because I’m trying to make sure that I’m not missing any key details, and also because it’s a field that I don’t know much about and one that’s dense with branches of math that I haven’t touched in a long time, such as calculus.

Whenever I do this, I use an older method for note-taking, namely an actual paper notebook, and preferably one that’s graph-ruled. Fortunately, the nearby Walmart is a reliable source. The notebooks they carry even look like the notebook that the hacker character Elliot uses in the Mr. Robot TV series, minus the damage incurred from the considerably more dangerous (if fictional) life that he leads:

For me, taking handwritten notes and working out all the details behind Karpathy’s description of the system that he’s building step by step in his video helps me get a solid understanding of how and why it works. It’s also so much easier to write equations and draw diagrams by hand…

…and of course, if you’re so inclined, you can easily enhance hand-written notes with comics:

In his videos, Karpathy does his level best to spell out every last little bit about how AI systems work. It’s impressive — he does explain AI programming better than most lecturers I’ve seen or books I’ve read.

But he’s also someone with a bachelor’s degree in computer science and physics, a masters in which he worked on computer simulations, and a PhD from Stanford where his area of study was some mash-up of computer vision and natural language processing. While he says that all you need to understand his video is a “basic knowledge of Python and a vague recollection of calculus from high school,” it’s pretty clear that he operates on a different level than the rest of us.

I have years of Python experience and took university-level calculus, but I still decided to not skip or skim over anything Karpathy covered. I followed the math in his “first principles” review of what a derivative is, and walked through the process of stepping through the neural network he introduced, which is essentially depth-first binary tree traversal. It’s straight from the standard “algorithms and data structures” course from the sophomore year of a computer science degree program, But hey, it never hurts to review stuff to make sure you truly understand it:

I’m thinking of putting out a series of videos to help people who don’t have a computer science and math background understand some of the stuff that Karpathy covers. It’ll be kind of like the help that Homer Simpson could’ve used when trying to understand marketing:

I’ll close with the first video in Karpathy’s series. If you have any questions about it, feel free to ask me — I’ll see if I can help!

Here’s your chance to learn mobile development where I learned mobile development, and at a sale price! RayWenderlich.com, the premier mobile developer tutorial site, is having a big Black Friday sale until December 2nd, and you don’t want to miss these bargains…

If you don’t want a bundle, the individual books are also available at sale prices. Don’t miss this opportunity — go check out the RayWenderlich.com store and get these bargains before they’re gone!

In the next couple of days, the 8th edition of iOS Apprentice — a great book for beginners who want to learn how to write iOS apps — will be available. I learned iOS programming from an earlier version, and fittingly enough, I wrote the first two sections of the upcoming edition.

In my sections, I show you how to write apps using SwiftUI, the new declarative Swift-based way of defining user interfaces for iOS and other Apple operating systems. This required me to not just revise the previous edition, but to rewrite my sections nearly from scratch. It was a lot of work, but it was enjoyable work, and I’m quite pleased with the results.

If you’d like a taste of what my section of the book is like, check out these sample videos from the RayWenderlich.com course called Your first iOS and SwiftUI app. It’s based on some of my chapters from iOS Apprentice, where you learn how to write your first app: a simple game called Bullseye. You can access the whole course with a subscription, which is a worthwhile investment.

And now, the sample videos…

Your First Programming Challenge: Making a Programming To-Do List

The course starts with a challenge: given a description of the game you’re about to develop, make a to-do list of tasks that you, as the programmer, will have to perform in order to have a completed app.

Getting Started with SwiftUI

Now that you’ve go a to-do list, it’s time to build your first Swift and SwiftUI app — an app that displays a button.

Objects, Data and Methods

Now that you’ve created your first app, you’ll need to learn a little programming theory and how it relates to the code behind the app.

Buttons and Actions

At this point, the app displays a button on the screen, but nothing happens when you press it. Let’s fix that.

Swift UI State

State is a key part of programming with SwiftUI. In this section, Ray introduces the concept of state and how it relates to how the SwiftUI draws the user interface.

Solving Code Problems

One of the biggest pitfalls when learning iOS development when something goes wrong. Here’s how you deal with these situations.

Portrait vs Landscape

In this section, you’ll learn about portrait and landscape modes, iDevice screen resolutions, and setting up the app so that it displays its content in landscape mode only.

Swift UI Views

This covers views, which are anything that’s drawn on the screen.

Swift UI Layout

You’ll learn the basic of laying out user interface elements on the app’s screens in this section.

Spacers and Padding

Cluttered interfaces aren’t as usable, so here come spacers and padding to the rescue!

Once again, you can watch the entire course (plus every other course and tutorial at RayWenderlich.com) with a subscription, and you can get this tutorial in book form soon when the book i co-wrote — iOS Apprentice, 8th edition — comes out in just a few days!

Sometimes, when it comes up in conversation that I know how to program Android and iOS applications, someone will say “Hey, I have an app idea — do you want to make it for me?” That’s why I laughed so hard at the most recent episode of Rick and Morty.

Here’s the opening scene from that episode:

In most cases, I politely demur — I can quite truthfully back out by saying “I’ve already got a lot on my plate right now.” Does this happen to you, and what do you do?