Skip to main content

Fourier Series Grapher

Here's a simple JavaScript + HTML program I wrote. It will graph a given number of terms of a Fourier series. To graph a Fourier series, type the appropriate expressions into the text fields and click "Update." The text fields support JavaScript, so you can write a whole function in there if you need to.

I also added some functions.
  1. even(x) - returns true if x is even, false otherwise.
  2. odd(x) - returns true if x is odd, false otherwise.
  3. power(x, a) - returns xa.
Some examples of input to try:
  • odd(k)?(2/k):0
  • even(k)?(4/k/PI):0
  • odd(k)?(4/(k+PI)/k):0
The default Fourier series is equal to sin(2.5x) on (-π, π).

Enjoy!




To receive updates, subscribe now!
Labels:

Comments

  1. Raheela KhanJuly 6, 2014 at 11:00 PM

    You're awesome! I'm teaching myself JavaScript along with HTML, JQuery, and CSS and your blog is very inspiring! I saw your program, "DRAW", on KhanAcademy and it was so cool! How did you learn how to make such great programs? I don't even know where to start-_-.

    Oh! And I'm a self-taught pianist as well*thanks to suzuki piano book, hehe*

    Keep up the great work!

    ReplyDelete
    Replies
    1. MathGeekJuly 7, 2014 at 6:33 PM

      Thanks for commenting! I started by learning BASIC (mostly from the documentation), and after that JavaScript came easily. I just had to learn the syntax and some object-oriented programming concepts.

      Of course, math is indispensable in programming. Looking at other programmers' source code can help with technique and structure, and practice helps a lot too.

      Usually I come up with an idea for a program first, and then I figure out how to write it. If I don't know how, I research it. It can take a while, but when I'm done I know a lot more about it than I did when I started.

      Good luck with programming!

      Delete

Post a Comment

Popular posts from this blog

Flipping Quarters

Here's an interesting puzzle involving chance: A man in a park asks you to play a game with him. It's a form of gambling. To play, you must pay the man $5, then flip a coin repeatedly until you get heads. As soon as you get heads, you stop flipping. If you only flipped the quarter once, he'll give you $1. If you flipped it twice, you get $2. Three times, $4. Four times, $8. Each extra flip gets you twice as much money, so the longer it takes before you get tails, the more money you get. Should you play, if you have a lot of time and the man will play as many games as you want? How much money, on average, would you gain (subtracting the $5 fee)? I will give the solution in a later post .
1 comment
Read more

Pluto No Longer on the Horizon

This morning, New Horizons became the first spacecraft to make a flyby observation of the Pluto system. During the mission, the spacecraft captured the most detailed photographs of Pluto's surface we've ever had, and possibly ever will have. It also found many new properties including size, mass, atmosphere, and surface composition. In a period of a few hours, we discovered more about Pluto than we've found in the 85 years since Clyde Tombaugh captured its first photograph. Before After  (images credit: NASA) To complete this mission, the spacecraft flew for more than 9 years through the emptiness of space. This may sound like a long time, but it's actually amazingly quick. In fact, New Horizons set the record for the fastest speed at launch, and during the flyby, the spacecraft was moving at a rate of over 30,000 mph, or roughly 50 times the speed of sound. Picture an object twice as heavy as a grand piano moving 25 times faster than a bullet from a gun. Yikes. The man...
2 comments
Read more

Should Tau Replace Pi?

The digits of π, organized in a very new way Happy π-day! And happy π-month! Today's month and day - that is, March 14 or 3.14 - includes the first 3 digits of π. And today's month and year - March 2014 or 3.14 - also includes the first 3 digits of π. We won't have another double-day for π for the next 100 years, so enjoy this one! For the special occasion, I'm posting two π-related posts - one for π-month, and the other for π-day. In both posts, I'm setting the font size to approximately π * π + π + π. This is the first post, for π-month; to see the second, go to http://greatmst.blogspot.com/2014/03/pi-month-pi-day-post-2-5-common-pi-myths.html . In this post, I am including an essay I wrote about whether π or τ is the more superior constant. This was written for people who know very little about math, so the basic idea should be easy to understand even for people who are not mathematically inclined. Should Tau Replace Pi? A constant is any number or value that ne...
Post a Comment
Read more