April 2007
Intermediate to advanced
1728 pages
47h 51m
English
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Chapter 53. Application: Calculations and Graphics
IN THIS CHAPTER
Precached images
Math calculations
CGI-like image assembly
When the scripting world had its first pre-release peeks at JavaScript (while Netscape was still calling the language LiveScript), the notion of creating interactive HTML-based calculators captured the imaginations of many page authors. Somewhere on the World Wide Web, you can find probably every kind of special-purpose calculation normally done by scientific calculators and personal computer programs—leaving only weather-modeling calculations to the supercomputers of the world.
In the search for my calculator gift to the JavaScript universe, I looked around for something more graphical. Numbers, by themselves, are pretty boring; so any way the math could be enlivened was fine by me. Having been an electronics hobbyist since I was a kid, I recalled the color-coding of electronic resistor components. The values of these gizmos aren't printed in plain numbers anywhere. You have to know the code and the meaning of the location of the colored bands to arrive at the value of each one. I thought that this calculator would be fun to play with, even if you don't know what a resistor is.
The Calculation
To give you an appreciation for the calculation that goes into determining a resistor's value, here is the way the system works. Colored bands are printed on the surface of a resistor to encode its resistance value in ohms. The first (leftmost) band is the tens digit; the ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.