## Math for Dummies

“Two Math for Dummies” books, from bizarro.com. :)

By Alvin Alexander. Last updated: November 24 2019

“Two Math for Dummies” books, from bizarro.com. :)

By Alvin Alexander. Last updated: April 16 2019

AskAMathematician.com has a good answer to, Why was it so hard to take a picture of a black hole?

By Alvin Alexander. Last updated: August 6 2018

If you’re into puzzles and games of math and logic, The Riddler looks like it will be a good book when it comes out.

By Alvin Alexander. Last updated: July 28 2018

“There’s only ONE rule, but it’s an important one: all of your values must be functions. Not *programming functions*, but *math functions*.”

I think I read that quote in an earlier version of this article. The quote is about functional programming, and it influenced something I wrote in my book, Functional Programming, Simplified: Functional programmers think about themselves as being mathematicians, and think of their code as being a combination of algebraic equations, where each function is a pure function that you can think of in mathematical terms.

By Alvin Alexander. Last updated: January 13 2020

This page contains a collection of examples of how to use Scala Vector class informational and mathematical methods. Note that these same methods will also work with a Scala `Seq`

, including `IndexedSeq`

.

As the name implies, these methods let you get information about the contents of a `Vector`

, or perform mathematical expressions on a `Vector`

.

By Alvin Alexander. Last updated: May 13 2018

Bloomberg has a story titled, The Gambler Who Cracked the Horse-Racing Code.

By Alvin Alexander. Last updated: May 11 2018

As a quick note, here’s a Java method that will round a `float`

to the nearest half value, such as 1.0, 1.5, 2.0, 2.5, etc.:

/** * converts as follows: * 1.1 -> 1.0 * 1.3 -> 1.5 * 2.1 -> 2.0 * 2.25 -> 2.5 */ public static float roundToHalf(float f) { return Math.round(f * 2) / 2.0f; }

The comments show how this function converts the example `float`

values to their nearest half value, so I won’t add any more details here. I don’t remember the origin of this algorithm — I just found it in some old code, thought it was clever, and thought I’d share it here.

By Alvin Alexander. Last updated: March 28 2018

Here’s an article with two interesting exercises near the end of it: How thinking about infinity changes kids’ brains on math. When you’re ready to go deeper, that article links to a NY Times article, Teaching the mathematics of infinity. And then that article links to another titled, The life of Pi and other infinities.

(When I was a young lad, I’d often lay in bed at night and wonder, “Okay, so I go to the edge of the universe ... what’s after that? There’s gotta be something after that, right?”)

By Alvin Alexander. Last updated: January 22 2020

I was just working on a math problem in Scala where I needed to get the exponent of a value, and after some research, I found that the right approach is to use the scala.math.pow function when you need the power/exponent of a value. Here's the output from a REPL command:

scala>scala.math.pow(2,3)res1: Double = 8.0

I was originally using the Math.pow function, and getting a *deprecation* warning:

By Alvin Alexander. Last updated: November 30 2017

I haven’t read it yet, but I just added Category Theory for Programmers to my “need to read” list.