easyRPN

easyRPN is a calculator based on RPN logic.

Introduction

In reverse Polish notation the operators follow their operands; for instance, to add 3 and 4, one would write "3 4 +" rather than "3 + 4". If there are multiple operations, the operator is given immediately after its second operand; so the expression written "3 − 4 + 5" in conventional notation would be written "3 4 − 5 +" in RPN: 4 is first subtracted from 3, then 5 added to it. An advantage of RPN is that it removes the need for parentheses that are required by infix. While "3 − 4 × 5" can also be written "3 − (4 × 5)", that means something quite different from "(3 − 4) × 5". In postfix, the former could be written "3 4 5 × −", which unambiguously means "3 (4 5 ×) −" which reduces to "3 20 −"; the latter could be written "3 4 − 5 ×" (or 5 3 4 − ×, if keeping similar formatting), which unambiguously means "(3 4 −) 5 ×".

Despite the name, reverse Polish notation is not exactly the reverse of Polish notation, for the operands of non-commutative operations are still written in the conventional order (e.g. "÷ 6 3" in Polish notation and "6 3 ÷" in reverse Polish both evaluate to 2, whereas "3 6 ÷" in reverse Polish notation would evaluate to ½).

About easyRPN calculator

This calculator supports most of the basic calculus with both real and imaginary numbers, math function, statistical operators, engineering conversions and some physical constants.

The most common math functions are split in several views that can be reached swiping in the direction that connects the following view.

Math

• EXP: exponential of x
• √x: square root of x
• x^2: square of x
• x^y: yth power of x
• 1/x: reciprocal of x
• LOG: natural logarithm of x
• LOG10: base 10 logarithm of x
• LOG2: base 2 logarithm of x
• SIN: trigonometric sine of x
• COS: trigonometric cosine of x
• TAN: trigonometric tangent of x
• ASIN: trigonometric arc-sine of x
• ACOS: trigonometric arc-cosine of x
• ATAN: trigonometric arc-tangent of x
• SINH: hyperbolic sine of x
• COSH: hyperbolic cosine of x
• TANH: hyperbolic tangent of x
• ASINH: hyperbolic arc-sine of x
• ACOSH: hyperbolic arc-cosine of x
• ATANH: hyperbolic arc-tangent of x
• ERF: Gauss's error function calculated at x
• ERFC: complementary Gauss's error function calculated at x

Stat

• MEAN: mean value of all the stack entries
• VAR: mean value of all the stack entries
• SDEV: standard deviation value of all the stack entries
• MAX: maximum value of all the stack entries
• MIN: minimum value of all the stack entries
• COUNT: number of stack entries
• FACT: factorial of x
• PERM: permutation P(x, y)
• COMB: combination C(x, y)

Bin

• AND: logic and between x and y
• OR: logic or between x and y
• NOT: logic 1's complement of x
• XOR: logic or exclusive between x and y
• LSL: logic shift left of x
• LSR: logic shift right of x
• ASL: arithmetic shift left of x
• ASR: arithmetic shift right of x
• ROL: logic rotation left of x with carry
• ROR: logic rotation right of x with carry

Stack

• CLEAR: clear all stack, log and display contents
• DROP: drop last entry in the stack
• SWAP: swap last two entries of the stack
• UP: roll-up the stack content
• DOWN: roll-down the stack content

Mode

• DEGREE: toggle between RAD(iant) and DEGREE
• BASE: select the numerical base from DEC(imal), HEX(decimal), BIN(ary) and OCT(al)

Numerical pad

• i: add the imaginary unit ‘j’ to current editing number.

User interaction

Swipe Gesture

The up to four directional arrows displayed during a screen transition or pressing for more than one second the screen background, shoe the allowed swipe gestures to move in the other screens

Tap Gesture

A tap gesture on the three stack display lines copies the corresponding value to the edit text field.

Long Press Gesture

A long press on the screen will show the allowed swipe directions again.

User interaction.

Not yet Available.

easyRCC v1.0 (...)

- First release.

Known bugs

1. Some unit conversions show wrong results:
   1. Area: the third column with the unit description results shifted of 1 position up because the ft2 is missing
2. ...

easyRPN v1.0 - Screenshots