42-ComputorV2

This project provides you an advanced maths interpreter interface highly inspired by Linux bc.

📦 Install

First, you'll need to get yourself node.js v16 and install some packages to get plotter dependency working as expected.

• Linux, use your distribution packets manager:

  $> sudo apt-get install gnuplot ghostscript

• macOS, use Homebrew:

  $> brew install gnuplot ghostscript

Then all you have to do is installing package dependencies:

$> npm install

💻 Usage

Run the interpeter with:

$> node computor.js

Run test suites with:

$> npm run tests

Features

• Computing:

  Handles simple expression with addition, substraction, multiplication, division, power and modulus operators with brakect priorities.

  > 2 + 23 * (8.23 / (2 - 7)) = ?
  

  It also supports complex numbers and unary operators.

  > -2.23 + (-2.1) / 3.08i = ?
  

  This evaluation algorithm also support variables which are explained bellow, both Numeral and Matrix variables are used in the same way, call its name and it will be evaluated before the whole input.

  > 57 + x / 723.2 = ?
  

  For Expression variables, you get to give them the right amount of parameters to evaluate their images.

  > 2.8211 * f(23) = ?
  

  All of the variable types supports unary operator which means you can get the opposite of any variable by putting a minus sign before in your input.

• Storing variables:

  This program allows you to compute and keep three different types of variables. First, Numeral, basically representing numbers from integers to complex ones.

  > x = -7.5 + 82i
  

  It computes the result of the left term and then assign it to the requested variable.

  Then we have Matrix type that holds 2D Matrix only.

  > m = [[ 2, 0, -3 ]; [ 7, 0.82, -12 ]]
  

  Supports other Numerals and Expression images as well (described bellow) in each term of the matrix.

  Finally, Expression which are simply functions that take variables.

  > f(x, y, z) = x - 6.2 / y + 2 * z
  

  You can create Expression with arbitrary number of variables, no limit.

• Builtins:

  Some common maths functions are reproduced and available to you, here's all of the supported functions. They can be used during input evaluation or variable assignation.

  Symbol	Function	Implementation	Coverage
  abs()	absolute value	Trivial on ℝ and uses Euclidian distance on ℂ	ℂ
  cos()	cosine	Taylor series	ℂ
  cosh()	hyperbolic cosine	Taylor series	ℂ
  exp()	exponential	Taylor series	ℂ
  deg()	radian to degree	radian * 180 / π	ℝ
  fact()	factorial	n! = n * (n - 1) * ... * 1	ℕ
  ln()	natural logarithm	Taylor series	ℝ+
  log()	logarithm base10	Long division algorithm	ℝ+
  rad()	degree to radian	degree * π / 180	ℝ
  sin()	sine	Taylor series	ℂ
  sinh()	hyperbolic sine	Taylor series	ℂ
  sqrt()	square root	Babylonian algorithm	ℝ

• Commands:

  You also have a selection of commands that you can use to your liking during program's context.

  Command	Details
  !commands	Shows you details about each command.
  !config	Shows current context configuration.
  !functions	Shows stored Expression elements.
  !help	Gives you more information about some errors that might occur at runtine.
  !history	Shows you the list of previous inputs you made.
  !matrices	Shows stored Matrix elements.
  !reset	Wipes everything stored and set default context configuration.
  !set	Allows you to tweak some options in configuration.
  !solve	Built-in quadratic equation solver.

🛠️ Configuration

This program allows you to modify some options to alter or augment some behaviours. Here is the list of all available options.

Option	Type	Description
env.errorStackTrace	Boolean	Toggles tracing error display.
env.historySize	Number	Sets the size of the list displayed using !history command.
env.silentMode	Boolean	Toggles display for a lot of things. Mainly for testing purposes.
equation.graph	Boolean	Toggles ploting equation on a graph when using !solve command.
equation.verbose	Boolean	Toggles intermediate computation display when using !solve command.
function.expensionCount	Number	Sets the number of iterations for Taylor series.
number.fractionForm	Boolean	Toggles fractionnal display. Useful when 𝑥 ∈ ℚ.
number.precision	Number	Sets the number of computed decimals.

Every single option listed above can be configured using the !set command.