Financial Math

A set of financial equations.

This library provides a set of financial equations. This library is based on the book titled:

Matemáticas financieras

El valor del dinero en el tiempo

by Zbigniew Kozikowski Zarska

Installation

Add this line to your application's Gemfile:

gem 'financial_math'

And then execute:

$ bundle

Or install it yourself as:

$ gem install financial_math

Content

This cover the next topics in financial math:

• Geometric Progression
• Arithemetic Progression
• Simple Interest
• Compound Interest

More content will be added, soon, like:

• Annuities
• Valuation
• Amortization
• Stock market math

Usage

To calculate the last item of a geometric progression:

progression = FinancialMath::GeometricProgression.new(initial_value: 1100, ratio: 1.1, times: 5)
progression.last_item

To calculate the future value:

class Accountant
  include FinancialMath::SimpleInterest
end

accountant = Accountant.new
accountant.future_value(present_value: 100_000.0, interest_rate: 0.05, periods: 3)

The interest rate must be in terms of years, if your problem is expressed in terms of days or months, provide the frequency of conversion and the periods in terms of days.

class Accountant
  include FinancialMath::SimpleInterest
end

accountant = Accountant.new
accountant.future_value(present_value: 1500.0, interest_rate: 0.45, periods: 3, frequency: 360)

Available simple interest formulas

Available compound interest formulas

Development

If want test this gem without clone this repo, type:

$ gem install financial_math --dev

This command will get the development dependencies installed too.

Release History

• 1.0.3
  • FIX: Fix bad release
• 1.0.2
  • ADD: Add version badge and fix some typos in README
• 1.0.1
  • FIX: Fix bad release
• 1.0.0
  • CHANGE: Remove SimpleInterest()
  • CHANGE: Remove CompoundInterest()
  • ADD: Add CompoundInterest sub-modules
  • ADD: Add SimpleInterest sub-modules
• 0.7.0
  • ADD: Add present_value, continous_present_value to CompoundInterest as public methods
  • ADD: Add internal_rate_of_return, real_rate_of_return and a_good_investment? to CompoundInterest as public methods
• 0.6.0
  • ADD: Add @frequency to SimpleInterest class
  • CHANGE: Change the periods_in_days mehtod to factor in SimpleInterest
• 0.5.0
  • ADD: Add average_growth_rate and continous_future_value public methods to CompoundInterest class
• 0.4.1
  • CHANGE: Update docs (module code remains unchanged)
• 0.4.0
  • ADD: Add CompoundInterest class
• 0.3.1
  • CHANGE: Update docs (module code remains unchanged)
• 0.3.0
  • ADD: Add SimpleInterest class
• 0.3.0
  • ADD: Add GEometricProgression class
• 0.2.0
  • ADD: Add ArithemeticProgression class
• 0.1.0
  • The first proper release
  • ADD: The basic file with basic equations
• 0.0.1
  • Work in progress

Meta

Daniel Omar Vergara Pérez – @dan1_net – daniel.omar.vergara@gmail.com

https://github.com/dany2691/

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/dany2691/financial_math. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

Contributing

1. Fork it (https://github.com/dany2691/financial_math/fork)
2. Create your feature branch (git checkout -b feature/fooBar)
3. Commit your changes (git commit -am 'Add some fooBar')
4. Push to the branch (git push origin feature/fooBar)
5. Create a new Pull Request

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the FinancialMath project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.