Tag: Math

Rick Wicklin 0
Visualize a torus in SAS

This article uses graphical techniques to visualize one of my favorite geometric objects: the surface of a three-dimensional torus. Along the way, this article demonstrates techniques that are useful for visualizing more mundane 3-D point clouds that arise in statistical data analysis. Define points on a torus A torus is

Students & Educators
Staci Lyon 0
Back to School: Math

Kicking off the new school year, you may be looking for ways to ease your students back into math. Here are a few ways that Curriculum Pathways can help. Math Stretch Need a fun, quick way for your students to develop their elementary math skills? Math Stretch provides activities targeting number

Learn SAS
Rick Wicklin 0
What is a moving average?

A moving average (also called a rolling average) is a statistical technique that is used to smooth a time series. Moving averages are used in finance, economics, and quality control. You can overlay a moving average curve on a time series to visualize how each value compares to a rolling

Rick Wicklin 0
Lo, how a polar rose e'er blooming

Lo how a rose e'er blooming From tender stem hath sprung As I write this blog post, a radio station is playing Chrismas music. One of my favorite Christmas songs is the old German hymn that many of us know as "Lo, How a Rose E're Blooming." I was humming

Rick Wicklin 0
The spiral of splatter

"Daddy, help! Help me! Come quick!" I heard my daughter's screams from the upstairs bathroom and bounded up the stairs two at a time. Was she hurt? Bleeding? Was the toilet overflowing? When I arrived in the doorway, she pointed at the wall and at the floor. The wall was

Rick Wicklin 0
Computing polar angles from coordinate data

Equations that involve trigonometric functions can have infinitely many solutions. For example, the solution to the equation tan(θ)=1 is θ = π/4 + kπ, where k is any integer. In order to obtain a unique solution to the equation, we define the "arc" functions: inverse trigonometric functions that return a

Rick Wicklin 0
The distribution of Pythagorean triples by angle

Last week I was chatting with some mathematicians and I mentioned the blog post that I wrote last year on the distribution of Pythagorean triples. In my previous article, I showed that there is an algorithm that uses matrix multiplication to generate every primitive Pythagorean triple by starting with the

Students & Educators
Staci Lyon 0
Celebrating Pi Day!

Pi is the ratio of a circle’s circumference to its diameter. Although it is a non-terminating, non-repeating number, the decimal approximation 3.14 and the fraction 22/7 are typically used to represent the irrational mathematical constant. The Greek letter π, was first used as the symbol for pi in 1706 by

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