07 Tuesday May 2019
Posted in CS101
In the last post, I explored different ways to model the logic of a full-adder. In this post I’ll explore a model of a physical instance of a full-adder — a model that simulates physical reality.
Because a full-adder is, at root, a mathematical expression, various software models can accomplish the same results. Models are abstractions, so the only thing a model can simulate perfectly is another model.
05 Sunday May 2019
Posted in CS101
Tags
finite state machine, FSA, FSM, full adder, half adder, Python, state engine, state table, truth table
I was involved in a debate recently about whether a full adder logic circuit is a computer. The computer science answer is: “No, not as we define a computer.”
I plan to address that answer in detail on my main blog. Here I wanted to show some of the different ways a full adder can be modeled and implemented.
22 Friday Mar 2019
Posted in Fun
This is a companion post to the Math Games #1 post on my main blog.
Here I present some code (Python, of course) for exploring the first two games, multiplicative persistence and the Collatz conjecture.
01 Tuesday Jan 2019
Posted in Fun
Tags
To ring in the new year I thought I’d play around with an old friend from my earliest programming days, a random text generator. Back then (over 30 years ago), but a little bit always, a good way to practice programming is by working on small, relatively easy, but still fun, programs.
Simple games are common choice, but not the only one. (I’ve probably written a version of Mastermind in every programming language I know.) Another fun choice is various image or text generators (or processors). Random text generators, in particular, offer a range of complexity depending on your taste and time.
14 Friday Sep 2018
Posted in Opinion
Tags
computer code, computer programmer, computer programming, real programmers, software design, software development, software industry
There’s a general ethic these days — that anyone can code — and like a lot of things, there’s some truth to it, but also some silliness. As usual, it really depends on what we mean by “anyone can code.”
If we mean it in the same way we might say, “anyone can drive,” I think it’s silly. But if we mean in the same way we might say, “anyone can doctor (or lawyer),” well, then I still think it’s silly.
11 Saturday Aug 2018
Posted in Opinion
Tags
computer programming, computer science, program, software, software design, software development, software industry, xkcd
I cracked up when I saw this recent xkcd cartoon. Randall Munroe rarely fails to deliver, but this one especially caught my eye. It’s painfully on-point and quite dismaying on at least two points:
Firstly, that it should still be this bad given all the time, money, and attention, it has received is reason alone for dismay. Part of the problem here may be that we haven’t admitted how hard software is to get right.
But, secondly, software is central to our lives now — far more than airplanes, and even more likely than elevator rides. You might ride an elevator, at most, a dozen times a day, but software enters your life more times than that.
Especially if you use a mobile computing device!
02 Wednesday Aug 2017
Posted in Stories
Sometimes ya gotta laugh. I just spent nearly an hour chasing one of those bugs that “can’t be happening” because “the code looks absolutely correct (as far as I can tell).” Of course, the bug, once you find it, was always hiding in plain view.
This time the fix involved adding just two characters, incidentally improving the program semantics, and very much reminded me of the old joke about the huge cargo ship that breaks down at sea…
20 Thursday Jul 2017
Posted in Blog
Tags
computer languages, computer programmer, data, Matplotlib, NOAA, programming language, Python, Pythonista, SQL, SQLite, xkcd
In the unlikely event anyone is reading this, and, more in the original spirit of “web logs“, as much a diary entry to record both the passing of time and the moment, after a long period of quiet, and in the long-winded run-on way that I sometimes have, a post.
19 Monday Dec 2016
Posted in CS101
Tags
computer language, computer languages, computer programming, computer science, GOTO statement, iteration, language design, loop statements, programming language, recursion
When it comes to what makes a computer (or any other) language a programming language, there are three characteristics usually required:
This post is just a brief note (for a friend) about the third item and why it allows three distinct options.
16 Tuesday Aug 2016
Posted in CS101
Tags
constants, defined values, global constants, literal values, literals, named constants, named values, numerical constants, P.J. Plauger, string constants
Along with “always use less-than” is another great piece of always advice, except this one is a prohibition, a never rather than an always (same thing, really, from a programmer’s point of view).
It has to do with never having literal values embedded in your code!
