42-ComputorV1

This project is a small equation solver. It was made using plotter to get a nice overview of the equation's shape.

Install

This program requires you to install node.js and few packages to get plotter to work as intended. On Linux simply use your packet-manager like:

$> sudo apt-get install gnuplot ghostscript

For macOS you must use Homebrew to install these packages as follow!

$> brew install gnuplot ghostscript

Once that's done clone the repository and init submodules using:

$> git clone --recurse-submodules https://github.com/kibotrel/42-ComputerV1

Finally, go in nodejs-plotter folder and run:

$> npm install

Usage

Run the program

Now that everything is installed you only have to use node to run the program with at least an equation to solve as argument like :

$> node computor.js equation="3 * X^1 - 2 * x^0 = 7 * X^2"

This command output information about the given equation such as its degree and its root(s) if possible.

Command line

• Flags:

  A comand line flag looks like :

  --flagName or -flagAlias

  It adds a boolean (flagName or flagAlias) set to true to the argument object.

• Variables

  A command line variable looks like :

  variableName="variableValue"

  It automatically adds a string (variableName) set to variableValue to the argument object.

Features

• Flags:

  Name	Alias	Description
  --complex	-c	Computes complex roots of quadratic equations
  --fraction	-f	Displays every single output as non reductible fraction
  --graph	-g	Plots the reduced equation on a graph exported as an image
  --help	-h	Displays a little built-in usage
  --natural	-n	Outputs values in a more common notation
  --pretty	-p	Makes program's output a lot more readable
  --verbose	-v	Adds in-between steps of the solving process to the output

• Variables:

  Name	Description
  equation	The equation to solve. It must follow this particular scheme: "Polynom1 ± ... ± PolynomN = PolynomN+1 ± ... ± PolynomN+M" Read more about it bellow.
  precision	The number of decimals to display in ouputed values. Set to 6 by default and ranges from 0 to 12 inclusive.

Equation

As stated above, the equation variable must be formated in some way in order for the program to parse it correctly. Each polynom is composed of a factor, X and its power noted as "factor * X^power" in the equation.

Example: "-8.6 * X^2"

The program handles a lot more than that and allows a more flexible way of inputing data. First, if power = 1 you can ommit this parameter for this particular polynom.

Example: "3 * X^1" becomes "3 * X"

It also understand that everything between a sign and the character X is considered as it's factor so you can ommit to put the multiply sign.

Example: "7.2 * X^3" becomes "7.2X^3"

If by any chance factor = 1 it can be, once again, ommited because it does not affect the value of the final polynom.

Example: "1 * X^2" becomes "X^2"

Likewise if power = 0 the whole X^factor part can be ommited because it results in multiplying factor by 1 which does nothing as well.

Example: "-5 * X^0" becomes "-5"

Of course, everything can be mixed and the whole remain understandable by the program. Here's a full example.

Example: "-6.72 * X + X^3 - 4X^0 - 7X = 9 + 2X^2 - 8.4X + 13"