A simple computer algebra system (for symbolic manipulation of simple mathematic formulas) written in SetlX.
- Download SetlX (follow instructions on the website to properly install it).
- Download this repo (or clone it)
- Open the terminal, move into this repo and run:
$ setlX
=> load("diff.stlx");
=> evalStr("3 * x * (x^2 + y)");
The following is a list of all operators and functions, that are currently implemented and how their syntax is written.
(Note: a, b are both placeholders for arbitrary expressions. x on the other hand is a placeholder for some variable name).
| Operation | Syntax |
|---|---|
| Addition | a + b |
| Subtraction | a - b |
| Multiplication | a * b |
| Division | a / b |
| Exponentiation | a ^ b |
| Negation | -a |
| Sine | Sin(a) |
| Cosine | Cos(a) |
| Derivative | Diff(a, x) |
You can use varibales in expressions. For example, diff(x^2, x) calculates the derivative of where-clause you can also substitute certain variables with specific values. For example, diff(x^2, a) where x = 3a + c will substitute x with 3a + c and calculate the derivative of
There are also built-in variables, that can be used for calculations. These include currently only Pi and e.
Any name starting with a lower-case letter is assumed to be a single character. Thus ab evaluates to two variables (a and b), which are multiplied together. To use variables or functions with longer names, you will need to capitalize the name (e.g. Pi instead of pi).