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roptimizationtraveling-salesman

TSP in R, with given distances

A simple distances table of 5 nodes, I want to apply TSP with it. It looks like this when open in Excel.

enter image description here

library(TSP)

distances <- read.csv(file="c:\\distances.csv", header=TRUE, sep=",")
distances <- as.dist(distances)

tsp <- TSP(distances)
tour <- solve_TSP(tsp)
tour

It warns me on the as.dist() line:

Warning messages:
1: In storage.mode(m) <- "numeric" : NAs introduced by coercion
2: In as.dist.default(distances) : non-square matrix

Also the solve_TSP() line:

Error in .solve_TSP(x, method, control, ...) : NAs not allowed!

How can I correct them? Thank you.

Solution

  • You need to set your first column as the row label (you currently have them as a column). This code below works.

    # Import distance matrix
library(readr)
distances <- read_csv("C:/distances.csv")

# Rename row labels
row.names(distances) <- distances$X1
distances$X1 <- NULL

# Run the TSP
distances <- as.dist(distances)
tsp <- TSP(distances)
tour <- solve_TSP(tsp)
tour