MathExpr.jl

MathExpr.jl provides (1) parser parseexpr for mathematical expressions using Julia's parser, and (2) exact methods for determinant and inverse for matrices (determinant and inverse).

Expressions supported by the parser include:

Unary operations: + and -
Binary operations: +, -, *, /, //, \, ^
Mathematical functions
- cos, sin, tan
- cosh, sinh, tanh
- exp, cis
- cospi, sinpi, cispi
- sqrt
- log
- abs, abs2, sign
- conj, real, imag, angle
Mathematical constants
- i, im
- pi, π

julia> using MathExpr

julia> parseexpr("cos(0.75π)+i*sin(0.5*pi)")
 -0.7071067811865475 + 1.0im

julia> parseexpr("[cos(0.1) sin(0.1); -sin(0.1) cos(0.1)]")
2×2 Array{Float64,2}:
  0.995004   0.0998334
 -0.0998334  0.995004

"Exact" determinant and inverse support matrices of integers and rational numbers.

julia> inverse([2 0; 1 2])
2×2 Array{Rational{Int64},2}:
  1//2  0//1
 -1//6  1//3

julia> determinant([2 0; 1 3])
6

Note that determinant and inverse are also defined for floating points. They simply call LinearAlgebra's det and inv.

julia> det([2.0 0.0; 1.0 3.0])
6.0

julia> inv([2.0 0.0; 1.0 3.0])
2×2 Array{Float64,2}:
  0.5       0.0
 -0.166667  0.333333

Installation

]registry add https://github.com/kyungminlee/KyungminLeeRegistry.jl.git
add MathExpr