iamsubhranil/expressioner2

A new version of the Expressioner project with regular grammer, syntax trees and visitor pattern

Expressioner2

A new version of the Expressioner project with regular grammer, syntax trees and visitor pattern

This program solves a given expression containing arbitrary number of unknown variables, with arbitrary precision output. It supports all common trigonometric functions : sin, cos and tan family of functions. It also supports several other common functions like sqrt, log and log10, exp etc. Finally, the program itself provides a set of common constants like PI, E etc. This program also carefully upscales the output datatype of an operation, with a strictly only-if-needed policy. Even so, any operation involving trigonometric functions, sqrt, log or such type of functions, a mixed mode operation, or the division operation will always result the datatype to be upscaled to BigDecimal. However, any simple arithmetic operation involving one or two BigIntegers, like addition, summation, multiplication, factorization will be performed and generated as integer expressions only.

Building

1. Clone the repo or download the source code as a zip file.
2. Do either a in directory or an out of directory build, I prefer doing the later because it keeps the tree clean.

$ mkdir build
$ cd build
$ cmake ..
$ make all

Running

1. Arguments

--precision or -p - Set the output precision of the program for the running instance

--rounding_mode or -r - Set the rounding mode from one of Java's valid RoundingModes ( Note : Either specifying the exact mode name or specifying its value as an integer will do)

2. Example

You can run the program with any combination of the arguments and even without any of them at all. If no argument is specified, the programs uses Java provided IEEE754 complaint DECIMAL128 precision, i.e. precision upto 34 digits after the decimal point, and HALF_EVEN rounding mode.

a) Run the program with an output precision upto 100 digits after the decimal point and rounding mode FLOOR

$ java -jar Expressioner.jar --precision=100 --rounding_mode=3
$ java -jar Expressioner.jar --precision 100 --rounding_mode 3
$ java -jar Expressioner.jar -p=100 -r=3
$ java -jar Expressioner.jar -p 100 -r 3

b) Run the program with default precision and rounding mode HALF_UP

$ java -jar Expressioner.jar -r HALF_UP

c) Run the program with default rounding mode and output precision upto 50 digits after the decimal point

$ java -jar Expressioner.jar -p 50