jonghough / symbolic_expressions

Just for fun evaluator of symbolic expressions in OCaml with Menhir. Handles trigonometric functions, derivatives and some integrals.

symbolic_expressions

Just for fun evaluator of symbolic expressions in OCaml with Menhir. Handles trigonometric functions, derivatives and some integrals.

to build

ocamlbuild -use-menhir -tag thread -use-ocamlfind -pkg core Main.native

##to run

./Main.native

##examples

simple differentiation

d(e^(3*X))

returns

3*(e^(3*X))

more complicated example

d((X^2)+e^(cos(X)))

returns

(2*X+-Sin(X)*(e^(Cos(X))))

The result is slightly ugly, but symbolically correct.

integration

integral (X^4)

returns

X^5/5

more complex integration

Integration is much more difficult to handle than differentiation. However, the parser will take a good stab at solving a reasonably complex problem (one that can be evaluated by integration by parts usually).

e.g. we want to integrate cos(x)x^2

integral((cos(X))*(X^2))

result:

Sin(X)*X^2-(-Cos(X)*X+Sin(X))

##Permissable expressions

• any integer value
• X - variable
• +,-,*,/,^ arithmetic operators
• Cos, Sin, Tan, Cot, Sec, Cosec trig functions
• e^ exponential
• log natural logarithm
• d, differentiate, derivative all differentiate the enclosed expression
• integral, integrate integrate the enclosed expression