kalker

A scientific calculator that supports math-like syntax with user-defined variables, functions, derivation, integration, and complex numbers.

GitHub Repo

Download

>> f(x) = x(3x + 1) ← Declare functions

>> a₁ = 1÷6 ← Declare variables

>> 6ia√(f'(a₁))← Derivation

1.4142135624i ≈ √2i ← Complex numbers

>> ∫(0, π, sin2ix, dx) + e^(πi) ÷ 3 ← Integration

-0.3333333333 + 133.3733807458i ≈ -1/3 + 133.3733807458i

>> Σ(0, 720, 1÷n!) ← Calculating sums

2.7182818285 ≈ e

Open a kalker session in a new tab

Features

Operators: +, -, *, /, !, %
Groups: (), ⌈ceil⌉, ⌊floor⌋, [iverson]
Pre-defined functions and constants
User-defined functions and variables
Derivation (prime notation) and integration (eg. integral(a, b, x dx)
The value of an integral is estimated using Simpson's 3/8 rule,
while derivatives are estimated using the symmetric difference quotinent (and derivatives of higher order can be a bit inaccurate as of now).
Complex numbers
Understands fairly ambiguous syntax. Eg. 2sinx + 2xy
Syntax highlighting
Piecewise functions: f(x) = { f(x + 1) if x <= 1; x otherwise }, pressing enter before typing the final "}" will make a new line without submitting. Semicolons are only needed when writing everything on the same line.
Different number bases: Either with a format like 0b1101, 0o5.3, 0xff
or a format like 1101_2. The latter does not support letters, as they would
be interpreted as variables
Completion for special symbols on tab
Sum function
Load files that can contain predefined variable and function declarations.
You can also have automatically loaded files

Usage

All the calculator features and how they're used.

Operators

+, -, *, /
! Factorial, eg. 5! gives 120
% Percent, eg. 5% gives 0.05, 10 + 50% gives 15
% Modulus (remainder), eg. 23 % 3 gives 2

Completion for special symbols

You can type special symbols (such as √) by typing the normal function or constant name and pressing tab.

* becomes ×
/ becomes ÷
_123 becomes ₁₂₃
asin, acos, etc. become sin⁻¹(), cos⁻¹(), etc
sqrt becomes √
deg becomes °
pi becomes π
sum becomes Σ()
integrate becomes ∫()
tau becomes τ
phi becomes ϕ
floor becomes ⌊⌋
ceil becomes ⌈⌉
gamma becomes Γ
( becomes ()

Variables

Variables are defined with the following syntax: name = value

Examples: x = 3/4

Functions

Functions are defined with the following syntax: name(param1, param2, etc.) = value

Examples: f(x) = 2x+3 A(x, y) = (xy)/2

They are used like this: name(arg1, arg2, etc.)

Examples: f(3) + 3 A(2, 3)

Derivation can be done like this: name'(arg1)

Examples: f'(3) + 3 sin'(pi)

Predefined functions

sin, cos, tan, cot, cosec, sec
sinh, cosh, tanh, coth, cosech, sech
asin, acos, atan, acot, acosec, asec
ashin, acosh, atanh, acoth, acosech, asech
abs, ceil or ⌈⌉, floor or ⌊⌋, frac, round, trunc
sqrt or √, cbrt, exp, log, ln, arg, Re, Im
gamma or Γ
asinh, acosh, atanh, acoth, acosech, asech
bitcmp, bitand, bitor, bitxor, bitshift
comb or nCr, perm or nPr
gcd, lcm
min, max, hypot
log Eg. log(1000, 10) is the same as log₁₀(1000)
root Eg. root(16, 3) is the same as ³√16
integrate Eg. integrate(0, pi, sin(x) dx) is the same as
sum Eg. sum(1, 4, 2n) is the same as

Constants

pi

π

3.14159265

e

2.71828182

tau

τ

6.2831853

phi

ϕ

1.61803398

Files

Kalker looks for kalker files in the system config directory.

Linux: ~/.config/kalker/
macOS: ~/Library/Application Support/kalker/ or ~/Library/Preferences/kalker
Windows: %appdata%/kalker/

If a file with the name default.kalker is found, it will be loaded automatically every time kalker starts. Any other files in this directory with the .kalker extension can be loaded at any time by doing load filename in kalker. Note that the extension should not be included here.