Dozenal Calculator

About

Simple Dozenal is a RPN dozenal calculator. 

Dozenal is base twelve (or duodecimal). Simple Dozenal does all math in dozenal by default, but will also support base ten. 

RPN, (Reverse Polish Notation), is the entry method that employs a stack with numbers entered first and operations after. It requires less keystrokes than infix formula type entry, as there's no parenthesis required. 

User Interface, normal keys & shifted keys

Portrait orientation shown. Landscape is similar (imagine top and bottom screen halves side by side).

Features

• Stack supporting Reverse Polish Notation (RPN), 4 registers

• Numbers in 64 bit double precision

• Numbers in radix base twelve (default), or ten

• Math, trigonometric, logarithmic, finance, probability operations

• On-screen keypad, or Command line

• Formats fixed, engineering; Places 2 to 15; Angles degrees, radians; Dozenal ten and eleven digit options: AB, ↊↋ (rotated 23), TE, δε (delta epsilon), τε (tau epsilon), XE, XL

• In app help with drop down navigation

• Stack and settings saved between uses

• Runs on any device with a browser in portrait orientation (shown) or landscape

Basic Operation

Startup: The calculator starts up with same stack contents and mode state from last shut down.

Stack: The stack has 4 registers. 

• T register (top)

• Z register

• Y register

• X register (display)

You push all numbers (on which you'll perform operations) onto the stack with 'enter' key (push). After a math or stack operation, the next number is automatically pushed onto stack (without 'enter' key).

Before performing a math operation, the stack is saved as last stack, and the operands (number(s), under which the operation operates), are popped from stack. The result is pushed onto stack. When more operands are popped than results pushed, 4 registers are maintained by pushing a copy of T to top of stack.

Stack operations: The stack is manipulated with yellow keys or typed lower case letters.

Numbers: You use the blue keys or typed digits to enter numbers. Letter digits are upper case. 

Math operations: For math operations, you use the orange keys, or typed lower case letters.

Shift key: The shift key will show another level of stack, number, and math operations.

Dozenal Information

There's a community of people who advocate using dozenal instead of decimal (base ten). A dozen is divisible by 2, 3, 4, 6, while ten is only divisible by 2, 5. There's a dozen months, a dozen hours in a half day. Each of our 4 fingers have 3 sections. This allows arithmetic in dozenal on our fingers. Measurement systems would be changed to powers of dozens rather than tens.

There's dozenal information at American dozenal society, and the British dozenal society. You can read my paper, The Mighty Dozen.

Revision History

Oct 2022, ver 1.3, Added key queue, cleaned up stack implementation, added portrait and landscape view, and added help page. 

Feb 2023, ver 1.4, Added base mode (doz or dec (base ten)), added format mode (fix or eng), places, angle mode (rad or deg), and ten, eleven digit options (A, B; or ↊, ↋;). In doz base mode, fractional separator is semicolon. In dec mode, fractional separator is dot. User stack and mode settings stored between uses (encrypted). Added shift key, and additional math commands for int, trigonometry, logarithms, and finance commands. Added app title and icon in browser tab. Added simpleDoz logo and fobsplace Apps logo images to help. Updated help with new features, and improved readability.

Mar 2023, ver 1.5, 1.6, 1.7, Added command button row, so now only 1 level of shift. Improved landscape and portrait display to use full screen real estate. Added probability functions. For ten, eleven digits, rotated 2, 3 are not supported on all devices, e.g. Android mobile devices. T, E added as an additional ten, eleven digit option (A, B; ↊, ↋; or T, E). Mode settings changed from toggle keys to drop down selectors.. On desktop, selectors and keys have hover highlight. Changed probability keys names, from 'fact', 'perm', 'comb' to 'n!', 'npr', 'ncr'. Fixed 'lasts' so restores stack and 'lastx' restores X register using current mode settings for display.  Added category selector for navigation through help text. Added keypad layout for 'dec' 0 + 3x3 grid. Keypad layout for 'doz' remains 3x4 grid.  Shift key toggles colors to signal shift state. Probability and finance keys switched positions to be more consistent with RPN Crunch layout. Optimized text and key sizes for phone use. Updated help for new changes. Added shifted keys screenshot to help.

Apr 2023, ver 1.8, Improved help.

May 2023, ver 1.9, fixed rounding error, e.g. 0;186A, places = 2, is now, 0;19, (not 0;18). Improved web app update help. Shift key when shifted is now colored cyan (rather than reddish orange, in order to respect the red reserved for danger convention). 

Jun 2023, ver 1.10, in help, explanation of key queue, and probability examples improved.

Aug 2023, ver 1.11, added XE, XL options for ten, elv symbols. TE become default ten, elv digits choice. Fixed digi (digits increment) change so selector display updates. Added digd (digits decrement) word command. Changed ten, elv symbol code to use baseConv lib, ver 12. Updated help to explain XE, XL, and digd. Help About version text uses base and digits settings. As state data structure has changed, a one time 'reset' is done at startup. This results in loss of prior state data (stack and settings return to default values).

Sep 2023, ver 1.12, added  ten, elv digit options:  δε (delta epsilon), τε (tau epsilon). Uses baseConv lib 14. All images hosted at imgbb.com, (rather than google drive) to improve reliability of image loading, and provide Firefox compatibility.

Aug 2024, ver 1.13, 1.14, embedded images into code. No more hosting service time out issues, imgbb.com. Improved server data storage/retrieval between uses. Updated browser icon retrieval.