# L-11 MCS 471 Fri 16 Sep 2022 : runjacobi.jl
# Interactive running of the method of Jacobi on a test system.

import Random # to fix the seed of the random numbers
include("jacobi.jl")

"""
Prompts the user for a dimension and then
generates a random matrix to test the Jacobi method.
"""
function main()
    print("Give the dimension : ")
    line = readline(stdin)
    dim = parse(Int, line)
    Random.seed!(123);
    mat = rand(dim, dim)
    # make the matrix diagonally dominant
    for i=1:dim
        mat[i, i] = 100*mat[i,i]
    end
    sol = ones(dim, 1)
    noise = 1.0e-4*rand(dim, 1)
    rhs = mat*sol
    wrk = sol + noise
    println("A random matrix :")
    show(stdout, "text/plain", mat); println("");
    sol, numit, nrmdx, fail = jacobi(mat, rhs, wrk)
    println("The solution after ", numit, " iterations :")
    for i=1:dim
        strsol = @sprintf("%.16e", sol[i])
        println(i, " : $strsol")
    end
    print("Estimated forward error : ", nrmdx)
    if fail
        println(" failed.")
    else
        println(" succeeded.")
    end
end

main()