Symbolic math expressions in Ruby
Ruby
Switch branches/tags
Nothing to show
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Failed to load latest commit information.
lib
test
.document
.gitignore
LICENSE
README.rdoc
Rakefile
VERSION
symbolic-math.gemspec

README.rdoc

symbolic

This is a proof-of-concept experiment to handle symbolic expressions in Ruby, inspired by Sage.

Symbolic expressions can be built with Ruby syntax in a symbolic block, by declaring variables with var:

symbolic do
  var :x
  expr = 2+x                         # now expr contains a symbolic expression
  puts expr                          # -> (2 + x)
  puts eval(expr)                    # -> (2 + x)
  self.x = 1.5
  puts eval(expr)                    # -> 3.5
  puts eval(expr/7)                  # -> 0.5
  var :y
  poly = 3*x**3 - x**2 - y*x + 7
  puts eval(poly)                    # -> ((7.875 - (y * 1.5)) + 7)
  puts eval(poly, :y=>5.0)           # -> 7.375
end

Functions can be defined with fun:

symbolic do
  fun(:sqr){|x| x*x}
  var :x
  expr = sqr(sin(x))
  puts expr             # -> sqr(sin(x))
  self.x = 1.5
  puts eval(expr)       # -> 0.994996248300223
end

Similar project

github.com/brainopia/symbolic is a similar, more complete project. Because of this the gem released by this project has been renamed to symbolic-math. Note that this project's pretensions are more limited than brainopia's; I only intend to play with syntax to do symbolic Math in Ruby, not to implement any relevant symbolic math functionality.

Note on Patches/Pull Requests

  • Fork the project.

  • Make your feature addition or bug fix.

  • Add tests for it. This is important so I don't break it in a future version unintentionally.

  • Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)

  • Send me a pull request. Bonus points for topic branches.

Copyright

Copyright © 2009 Javier Goizueta. See LICENSE for details.