diff --git a/README.md b/README.md index 8fb5541..64eb5f6 100644 --- a/README.md +++ b/README.md @@ -5,4 +5,53 @@ -# LSODA.jl ## Introduction **LSODA.jl** is a Julia package that interfaces to the [liblsoda](https://github.com/sdwfrost/liblsoda) library, developped by [Simon Frost](http://www.vet.cam.ac.uk/directory/sdf22@cam.ac.uk) ([@sdwfrost](http://github.com/sdwfrost)), thereby providing a way to use the LSODA algorithm from Linda Petzold and Alan Hindmarsh from [Julia](http://julialang.org/). **Clang.jl** has been used to write the library and **Sundial.jl** was a inspiring source. ## Installation To install this package, run the command `Pkg.clone("https://github.com/rveltz/LSODA.jl.git")` ## Simplified Functions To solve an ODE, one can call the simplified solver: ```julia function rhs!(t, x, ydot, data) ydot[1]=1.0E4 * x[2] * x[3] - .04E0 * x[1] ydot[3]=3.0E7 * x[2] * x[2] ydot[2]=-ydot[1] - ydot[3] nothing end y0 = [1.,0.,0.] tspan = [0., 0.4] res = lsoda(rhs!, y0, tspan, reltol= 1e-4, abstol = Vector([1.e-6,1.e-10,1.e-6])) ``` To reproduce the test example from liblsoda, on can use: ```julia lsoda_0(rhs!, y0, tspan, reltol= 1e-4, abstol = Vector([1.e-6,1.e-10,1.e-6])) ``` This should give the following. ``` at t = 4.0000e-01 y= 9.851712e-01 3.386380e-05 1.479493e-02 at t = 4.0000e+00 y= 9.055333e-01 2.240655e-05 9.444430e-02 at t = 4.0000e+01 y= 7.158403e-01 9.186334e-06 2.841505e-01 at t = 4.0000e+02 y= 4.505250e-01 3.222964e-06 5.494717e-01 at t = 4.0000e+03 y= 1.831976e-01 8.941774e-07 8.168016e-01 at t = 4.0000e+04 y= 3.898729e-02 1.621940e-07 9.610125e-01 at t = 4.0000e+05 y= 4.936362e-03 1.984221e-08 9.950636e-01 at t = 4.0000e+06 y= 5.161832e-04 2.065786e-09 9.994838e-01 at t = 4.0000e+07 y= 5.179811e-05 2.072030e-10 9.999482e-01 at t = 4.0000e+08 y= 5.283524e-06 2.113420e-11 9.999947e-01 at t = 4.0000e+09 y= 4.658945e-07 1.863579e-12 9.999995e-01 at t = 4.0000e+10 y= 1.423392e-08 5.693574e-14 1.000000e+00 ``` +# LSODA.jl + +## Introduction + +**LSODA.jl** is a Julia package that interfaces to the [liblsoda](https://github.com/sdwfrost/liblsoda) library, developped by [Simon Frost](http://www.vet.cam.ac.uk/directory/sdf22@cam.ac.uk) ([@sdwfrost](http://github.com/sdwfrost)), thereby providing a way to use the LSODA algorithm from Linda Petzold and Alan Hindmarsh from [Julia](http://julialang.org/). **[Clang.jl](https://github.com/ihnorton/Clang.jl)** has been used to write the library and **[Sundials.jl](https://github.com/JuliaDiffEq/Sundials.jl)** was a inspiring source. + +## Installation + +To install this package, run the command `Pkg.clone("https://github.com/rveltz/LSODA.jl.git")` + +## Simplified Functions + +To solve an ODE, one can call the simplified solver: + +```julia +function rhs!(t, x, ydot, data) + ydot[1]=1.0E4 * x[2] * x[3] - .04E0 * x[1] + ydot[3]=3.0E7 * x[2] * x[2] + ydot[2]=-ydot[1] - ydot[3] + nothing +end + +y0 = [1.,0.,0.] +tspan = [0., 0.4] +res = lsoda(rhs!, y0, tspan, reltol= 1e-4, abstol = Vector([1.e-6,1.e-10,1.e-6])) +``` + + +To reproduce the test example from liblsoda, on can use: + +```julia +lsoda_0(rhs!, y0, tspan, reltol= 1e-4, abstol = Vector([1.e-6,1.e-10,1.e-6])) +``` + +This should give the following. + +``` +at t = 4.0000e-01 y= 9.851712e-01 3.386380e-05 1.479493e-02 +at t = 4.0000e+00 y= 9.055333e-01 2.240655e-05 9.444430e-02 +at t = 4.0000e+01 y= 7.158403e-01 9.186334e-06 2.841505e-01 +at t = 4.0000e+02 y= 4.505250e-01 3.222964e-06 5.494717e-01 +at t = 4.0000e+03 y= 1.831976e-01 8.941774e-07 8.168016e-01 +at t = 4.0000e+04 y= 3.898729e-02 1.621940e-07 9.610125e-01 +at t = 4.0000e+05 y= 4.936362e-03 1.984221e-08 9.950636e-01 +at t = 4.0000e+06 y= 5.161832e-04 2.065786e-09 9.994838e-01 +at t = 4.0000e+07 y= 5.179811e-05 2.072030e-10 9.999482e-01 +at t = 4.0000e+08 y= 5.283524e-06 2.113420e-11 9.999947e-01 +at t = 4.0000e+09 y= 4.658945e-07 1.863579e-12 9.999995e-01 +at t = 4.0000e+10 y= 1.423392e-08 5.693574e-14 1.000000e+00 +```