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Web Calculator 5

by brettfo Sat, 30 Jun 2012 4:55 pm EDT
Category: 
Last Updated: 
2012-08-23
Current Version: 
1.1.1
Requires Root: 
No
Developer: 
brettfo
Distribution: 
Available via Repository
Total Downloads: 
72
Your rating: None Average: 2.5 (2 votes)

Description

Expression evaluator

The expression evaluation part of the calculator should be easy enough to figure out; you give it an expression an it'll evaluate it if possible. Some examples include:
3+4*2 -> 11 (notice that order of operations are observed)
4! -> 24
2^3 -> 8
sqrt(4) -> 2

Note that I also define 2 constants, e and pi that evaluate to exactly what you think they should. The rest of the evaluator should be easy enough to pick up with the exception of the sum() function: I wanted a way to compute summations so the arguments to this function seem a little odd at first. As an example, consider one of the many methods of approximating the natural constant e: the sum of the quantity one divided by x factorial, with x from zero to (some upper bound.) This could be entered like:
sum(1/x!,x,0,10)
and will yield 2.7182818011463845
Note that the variable x in this case is arbitrary. I could do the same thing with the variable taco:
sum(1/taco!,taco,0,10)

Graphing

Switching into the graphing mode via the button up top will show an empty graph. Simply enter any function with x as the independent variable and hit the equals sign to see the graph. Simple as that. When many graphing calculators draw a function with a vertical asymptote such as 1/x or tan(x) they will accidentally draw a vertical line where the graph really shouldn't have one. I've made what I think to be a pretty good effort at avoiding these anomalies.

More Screenshots

License

Closed Source - Learn More

Availability

Free forever

Download options

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Discussion, Changelog, and Support

Discuss this app, get support, and read the changelog for Web Calculator in the Official Forum thread

5 Comments

Not bad, but a little incomplete for a scientific calculator:

- How do you enter a number in exponential notation, e.g., 2e15 ?
- No memory?
- No deg/rad selection?

I really enjoyed this app and was very useful to me as a student. Very efficient tool, have always used this. - Scott Sohr

Excellent ideas. I'm out of town visiting family for the next 2 weeks but as soon as I'm home I'll implement these.

when I download it said can not open mime any help please

kbail.29, by your error message it sounds like you're trying to download the ipk file directly on your TouchPad, and as far as I know that's not a supported scenario.  To load this you can either 1) download the ipk to your computer then use the developer tools from developer.palm.com to load it onto your TouchPad, or 2) install PreWare and make sure the precentral feed is loaded and search for it there.  The forums should have the instructions on installing PreWare.