solve problem by coordinates and .tsp file

README.md

@@ -21,7 +21,10 @@ Currently, this package works in 64-bit operations systems of Windows 10, macOS,
 
 # Usage
 
-Currently, only support symmetric problems. 
+Only symmetric problems are supported. 
+
+
+## Using a distance matrix
 
 ```julia
 M = [
@@ -32,9 +35,28 @@ M = [
 ]
 opt_tour, opt_len = solve_tsp(M)
 ```
-
 The distance matrix `M` must be integer-valued.
 
+## Using coordinates
+
+```julia
+n_nodes = 10
+x = rand(n_nodes) .* 10000
+y = rand(n_nodes) .* 10000
+opt_tour, opt_len = solve_tsp(x, y; dist="EUC_2D")
+```
+where `dist` is a choice of the distance function. 
+
+Available `dist` functions are listed in `[TSPLIB_DOC.pdf](http://akira.ruc.dk/~keld/research/LKH/LKH-2.0/DOC/TSPLIB_DOC.pdf)`. (Some may have not been implemented in this package.)
+
+## Using an input file 
+
+Using the [TSPLIB format](http://akira.ruc.dk/~keld/research/LKH/LKH-2.0/DOC/TSPLIB_DOC.pdf):
+```julia
+opt_tour, opt_len = solve_tsp("gr17.tsp")
+```
+The returned `opt_len` value is `-1`. At this moment, it is a user's responsibility to calculate the length of the optimal tour.
+
 # Related Projects
 
 - [Concorde.jl](https://github.com/chkwon/Concorde.jl): Julia wrapper of the [Concorde TSP Solver](http://www.math.uwaterloo.ca/tsp/concorde/index.html).

src/Concorde.jl

@@ -3,6 +3,7 @@ module Concorde
 using Random, LinearAlgebra
 
 include("../deps/deps.jl")
+include("dist.jl")
 # Write your package code here.
 
 function read_solution(filepath)
@@ -89,6 +90,64 @@ function solve_tsp(dist_mtx::Matrix{Int})
 end
 
 
+function solve_tsp(x::Vector{Float64}, y::Vector{Float64}; dist="EUC_2D")
+    n_nodes = length(x)
+    @assert length(x) == length(y)
+
+    name = randstring(10)
+    filepath = name * ".tsp"
+
+    open(filepath, "w") do io
+        write(io, "NAME: $(name)\n")
+        write(io, "TYPE: TSP\n")
+        write(io, "COMMENT: $(name)\n")
+        write(io, "DIMENSION: $(n_nodes)\n")
+        write(io, "EDGE_WEIGHT_TYPE: $(dist)\n")
+        write(io, "EDGE_WEIGHT_FORMAT: FUNCTION \n")
+        write(io, "NODE_COORD_TYPE: TWOD_COORDS \n")
+        write(io, "NODE_COORD_SECTION\n")
+        for i in 1:n_nodes
+            write(io, "$i $(x[i]) $(y[i])\n")
+        end
+        write(io, "EOF\n")
+    end
+
+    status = run(`$(Concorde.CONCORDE_EXECUTABLE) $(filepath)`, wait=false)
+    while !success(status)
+        # 
+    end
+
+    sol_filepath =  name * ".sol"
+    opt_tour = read_solution(sol_filepath)
+    opt_len = tour_length(opt_tour, dist_matrix(x, y, dist=dist))
+
+    cleanup(name)
+
+    return opt_tour, opt_len
+end
+
+function solve_tsp(tsp_file::String)
+    if !isfile(tsp_file)
+        error("$(tsp_file) is not a file.")
+    end
+
+    name = randstring(10)
+    filepath = name * ".tsp"
+    cp(tsp_file, filepath)
+
+    status = run(`$(Concorde.CONCORDE_EXECUTABLE) $(filepath)`, wait=false)
+    while !success(status)
+        # 
+    end
+
+    sol_filepath =  name * ".sol"
+    opt_tour = read_solution(sol_filepath)
+    opt_len = - 1 # Need to implement the calculation of the obj function
+
+    cleanup(name)
+
+    return opt_tour, opt_len
+end
 
 
 export solve_tsp

src/dist.jl

@@ -0,0 +1,63 @@
+function nint(x::Float64)
+    return round(Int, x)
+end
+
+function geo_coordinate(x, y)
+    PI = 3.141592
+
+    deg = nint(x)    
+    m = x - deg
+    latitude = PI * (deg + 5.0 * m / 3.0) / 180.0
+
+    deg = nint(y)
+    m = y - deg
+    longitude = PI * (deg + 5.0 * m / 3.0) / 180.0 
+
+    return latitude, longitude
+end
+
+function distance2D(xi, yi, xj, yj; dist="EUC_2D")
+    if dist == "EUC_2D"
+        xd = xi - xj
+        yd = yi - yj
+        return nint(sqrt(xd*xd + yd*yd))
+    elseif dist == "MAN_2D"
+        xd = abs(xi - xj)
+        yd = abs(yi - yj)
+        return nint(xd + yd)
+    elseif dist == "MAX_2D"
+        xd = abs(xi - xj)
+        yd = abs(yi - yj)
+        return max(nint(xd), nint(yd))      
+    elseif dist == "GEO"
+        lat_i, long_i = geo_coordinate(xi, yi)
+        lat_j, long_j = geo_coordinate(xj, yj)
+        RRR = 6378.388
+        q1 = cos(long_i - long_j)
+        q2 = cos(lat_i - lat_j)
+        q3 = cos(lat_i + lat_j)
+        dij =  RRR * acos( 0.5*((1.0+q1)*q2 - (1.0-q1)*q3) ) + 1.0
+        return floor(Int, dij) 
+    else
+        error("Distance function $dist is not supported.")
+    end
+end
+
+function dist_matrix(x::Vector{Float64}, y::Vector{Float64}; dist="EUC_2D")
+    n_nodes = length(x)
+    @assert length(x) == length(y)
+
+    M = Matrix{Int}(undef, n_nodes, n_nodes)
+
+    for i in 1:n_nodes
+        for j in i:n_nodes
+            if i == j 
+                M[i, j] = 0 
+            else
+                M[i, j] = distance2D(x[i], y[i], x[j], y[j]; dist=dist)
+                M[j, i] = M[i, j]
+            end
+        end
+    end
+    return M
+end

test/runtests.jl

@@ -1,14 +1,6 @@
 using Concorde
 using Test
 
-# @testset "Concorde.jl" begin
-#     A = Cint.([4, 2, 5, 7, 2, 1, 3, 5])
-#     ccall((:CCutil_int_array_quicksort, Concorde.LIB_CONCORDE), Cvoid, (Ref{Cint}, Cint), A, length(A))
-#     @test A[1] == minimum(A)
-#     @test A[end] == maximum(A)
-# end
-
-
 @testset "Concorde.jl" begin
     @testset "Symmetric TSP" begin
         M = [
@@ -31,4 +23,16 @@ using Test
         ]
         @test_throws ErrorException solve_tsp(M)
     end
+
+    @testset "Coordinates" begin
+        n_nodes = 10
+        x = rand(n_nodes) .* 10000
+        y = rand(n_nodes) .* 10000
+        opt_tour, opt_len = solve_tsp(x, y; dist="EUC_2D")
+    end
+
+    @testset "Input File" begin
+        opt_tour, opt_len = solve_tsp("gr17.tsp")
+        @test opt_len == -1
+    end    
 end