David Wanqian Liu :: Java -- PRECISE calculator

PRECISE calculator

Why PRECISE?

PRECISE stands for PRogrammable Expression-based Calculator with Intuitive Systematic Expandability. The source code is free to be redistributed and/or modified for noncommercial usage under the terms of the GNU General Public License. Feel free to contact me if you have any questions or great ideas concerning expanding the current product. I will provide a list of things-to-be-done later in this document.

How to use PRECISE

Keys

The meaning of keys can be found by simply placing the mouse on top of that key. If the key is sensitized, the semantics of the current key should be printed at the bottom of the PRECISE calculator. Key "Shift" is used to alternate every key's definition. If a key has multiple meanings, two labels will be displayed on it, one on the top and the other on the bottom. White colored label is the current key's name, whereas blue colored label is disabled. By pressing "Shift" key, every key's white and blue colored labels will switch color with each other. If a key has one single meaning, "Shift" key does not apply to it.

Modes

Currently, PRECISE supports three modes: The current mode of the calculator can be switched by pressing "Mode" key. Current mode is display in title bar at the top of the calculator.
Numberical Calculation Mode
This is the simplest mode in PRECISE calculator, devoted mostly to simple numerical calculations. Click "Mode" key multiple times until the title bar indicates the calculator is currently in numerical calculation mode. Most of every-day useful functions are supported under this mode (notice that each key has two functions in it). Try the following sequence:

"ENTER" key is same as "=" sign used in many now-a-day calculators. "DEL" key can be used to retype a large number if miss type occurs. "AC" is used to clean the current calculation and start a new round of inputs.

After you pressed "ENTER" key, the result of last input should be displayed, otherwise the specific error would be displayed on the upper half graphing area. Re-enter your input if a mistype might have occured. You may reuse the result of last calculation if you immediately apply one of five operators(+-*/^) to it. Otherwise a new round of calculation is started. Try following examples:

Expression Evaluation Mode
Expression evaluation mode is somewhat similar to the numerical calculation mode, except that the evaluation of an expression is done only when you pressed "ENTER" key. The input echo area in the middle of the calculator becomes editable when you are in "expression evaluation mode". You can either use key pad to enter your expression, or just type in your expression using keyboard. Try following examples:
Graphic Plotting Mode
When you switch to "graphics plotting mode", four keys will be enabled: "[", ",", "]", and "X". The first three keys are used to specify x range or the expression you want to plot. "X" is the self-variable you used to specify the function f(X). The input method is same as what is used in "expression evaluation mode", except that at the end of the expression, a range specification needs to be added. The standard format would be: f(X)[x-min, x-max], where f(X) is a expression containing "X", x-min and x-max are constant value expressions (does not contain "X"). If you do not specify "[x-min, xmax]", x range of [-1,1] will be assumed. Try following examples:

Things To Be Done

If you have anything else in mind, or would like to work on any of these enhancement with me, let me know. All source code and documentation can be found in next section.

Source and Documentation

Tar'ed and gziped calc.tar.gz. Save the above link, unzip and untar it, you should find the following: Here is the javadoc generate PRECISE package documentation.
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