1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
#######################################################################
# TSP - Traveling Salesperson Problem
# Copyrigth (C) 2011 Michael Hahsler and Kurt Hornik
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
## read a simple TSPLIB format file
read_TSPLIB <- function(file, precision = 0) {
## TSP or ATSP
type <- NULL
lines <- readLines(file)
## get info
metadata <- grep(":", lines)
info <- list()
lapply(strsplit(lines[metadata], "[[:space:]]*:[[:space:]]*"),
FUN = function(x) {
x[2] <- sub("[[:space:]]*$","",x[2]) ## kill trailing spaces
info[[toupper(x[1])]] <<- toupper(x[2])
})
## check
if(substr(info$TYPE, 1, 3) == "TSP") type <- "TSP"
else if(substr(info$TYPE, 1, 3) == "ATS") type <- "ATSP"
else stop ("Currently the only implemented TYPEs are TSP and ATS(P)!")
dim <- as.integer(info$DIMENSION)
if(info$EDGE_WEIGHT_TYPE == "EXPLICIT") {
## get data
data_start <- grep("EDGE_WEIGHT_SECTION", lines, ignore.case = TRUE)
if(length(data_start) == 0) stop("EDGE_WEIGHT_SECTION missing")
data <- lines[(data_start+1):length(lines)]
data <- sub("EOF", "", data, ignore.case = TRUE) ## kill optional EOF
data <- sub("^[[:space:]]*", "", data)## kill leading spaces
data <- strsplit(paste(data, collapse = " "), "[[:space:]]+")[[1]]
if(info$EDGE_WEIGHT_FORMAT == "FULL_MATRIX")
data <- data[1:(dim^2)]
else if(info$EDGE_WEIGHT_FORMAT == "UPPER_ROW"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_COL"
|| info$EDGE_WEIGHT_FORMAT == "UPPER_COL"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_ROW")
data <- data[1:(dim*(dim-1)/2)]
else if(info$EDGE_WEIGHT_FORMAT == "UPPER_DIAG_ROW"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_DIAG_COL"
|| info$EDGE_WEIGHT_FORMAT == "UPPER_DIAG_COL"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_DIAG_ROW")
data <- data[1:(dim^2/2)]
data <- as.numeric(data)
if(precision != 0) data <- data / 10^precision
## ATSP
if(type == "ATSP") {
if(info$EDGE_WEIGHT_FORMAT == "FULL_MATRIX"){
## todo: find out if FULL_MATRIX is row or column oriented?
data <- matrix(data, ncol = dim)
}else stop("ATSP needs EDGE_WEIGHT_FORMAT FULL_MATRIX!")
return(ATSP(data))
}
## TSP
## we have only symmetric data here!
if(info$EDGE_WEIGHT_FORMAT == "FULL_MATRIX") {
data <- as.dist(matrix(data, ncol = dim))
}else if(info$EDGE_WEIGHT_FORMAT == "UPPER_ROW"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_COL") {
class(data) <- "dist"
attr(data, "Size") <- dim
attr(data, "Diag") <- FALSE
attr(data, "Upper") <- FALSE
}else if(info$EDGE_WEIGHT_FORMAT == "UPPER_DIAG_ROW"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_DIAG_COL") {
## kill diag
kill <- cumsum(c(1, rev(2:dim)))
data <- data[-kill]
class(data) <- "dist"
attr(data, "Size") <- dim
attr(data, "Diag") <- FALSE
attr(data, "Upper") <- FALSE
}else if(info$EDGE_WEIGHT_FORMAT == "UPPER_COL"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_ROW") {
class(data) <- "dist"
attr(data, "Size") <- dim
attr(data, "Diag") <- FALSE
attr(data, "Upper") <- TRUE
}else if(info$EDGE_WEIGHT_FORMAT == "UPPER_DIAG_COL"
|| info$EDGE_WEIGHT_FORMAT == "LOWER_DIAG_ROW") {
## kill diag
kill <- cumsum(1:dim)
data <- data[-kill]
class(data) <- "dist"
attr(data, "Size") <- dim
attr(data, "Diag") <- FALSE
attr(data, "Upper") <- TRUE
}else stop("The specified EDGE_WEIGHT_FORMAT is not implemented!")
return(TSP(data))
} else if (info$EDGE_WEIGHT_TYPE == "EUC_2D" ||
info$EDGE_WEIGHT_TYPE == "EUC_2D") {
data_start <- grep("NODE_COORD_SECTION", lines, ignore.case = TRUE)
if(length(data_start) == 0) stop("NODE_COORD_SECTION missing")
data <- lines[(data_start+1):(data_start+dim)]
data <- matrix(as.numeric(unlist(strsplit(data, split="\\s+"))),
nrow = dim, byrow = TRUE)
data <- data[,-1]
return(ETSP(data))
}
stop("EDGE_WEIGHT_TYPE not implemented! Implemented types are EXPLICIT, EUC_2D and EUC_3D")
}
|
