GCalc: Free Online Graphing Calculator

About GCalc


GCalc.net is the home of the online graphing calculator, GCalc. This web site provides one of the best mathematical graphing utility available to thousands of teachers and students from all over the globe.

And all this is free!

The GCalc project aims to provide the world with an affordable alternative to commerical graphing calculators for mathematics education.

Philosophy & History

The original and the primary reason for GCalc is simply because I could make it. Ever since I learned to write computer programs, I've been using computers to help me with math. During the summer of 1998, after my freshman year at college, a friend and I worked out how to parse an expression that a user might type in. To test it out, I wrote a simple graphing canvas that drew whatever polynomial I fed it. So GCalc was born...

Of course, now GCalc has been endowed with many more features. The introduction of symbolic differentiation was very exciting. It's always exciting to be able to apply what you learn in school. Recursion is your friend! In addition to symbolic differentiation, GCalc 2 also featured a better GUI interface using Java AWT, including many instant zooms, function management, tracing, etc...

Development on GCalc is a slow business, mostly because I'm busy in school. But, finally GCalc 3 began to take shape in 2004 and then will be released officially in 2005. It's a complete rewrite of every line of code, featuring a Java Swing GUI interface, which a lot slicker than AWT. It also features a pluggable infrastructure so other people can eventually help bring more features to GCalc. The improvements over GCalc 2 are too many to name.

Somewhere in all of this, my perspective changed. I was no longer a student who needed a graphing calculator. Ideally, I think this is a point where we ought to take every math student. In ages past, people learned their multiplication tables. Now students have calculators to do extremely simple calculations like 6 times 8. They consider the know-how to punch in 4 buttons into a little appliance to be the mastery of the multplication tables. This is pathetic.

So I am torn between being the creator of this neat little gadget called GCalc and being pedagogically opposed to students using graphing calculators without knowing how to create and interpret graphs. The tension gets even greater as I incorporate increasingly more advanced features. I sincerely hope I am doing good by sharing GCalc with the world.

One thing that I don't feel guilty about is the price. GCalc is free for the whole world to use--that is, if you have a computer. Contrast this to the commercial graphing calculators. It is a fact that my decade old TI-85 was about $100. A comparable model is still $100. In those 10 years, computing power has increased a hundred-fold. Something really does not add up. My hope is to create an alternative option for those who want more for their money.

Lead Developer —
Jiho Kim

GCalc is the brain-child of Jiho Kim, who is currently a graduate student in mathematics at Indiana Unversity. GCalc began as a summer project after his first year at Pacific Lutheran Unversity, where he received degrees in mathematics and computer science.

Besides GCalc, Jiho has been involved in several other software projects, including:

When he is not busy doing mathematics and programming, Jiho enjoys volunteering, being active in the church, reading, and spending time with his family and friends.


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