// ReadGraphTable reads data and allocate graph
func ReadGraphTable(fname string, bargera bool) *Graph {
// data
var ne int
var edges [][]int
var weights []float64
// Bar-Gera format files from: http://www.bgu.ac.il/~bargera/tntp/
if bargera {
k := 0
reading_meta := true
io.ReadLines(fname, func(idx int, line string) (stop bool) {
if len(line) < 1 {
return false
}
line = strings.TrimSpace(line)
if line[0] == '~' {
return false
}
if reading_meta {
switch {
case strings.HasPrefix(line, "<NUMBER OF LINKS>"):
res := strings.Split(line, "<NUMBER OF LINKS>")
ne = io.Atoi(strings.TrimSpace(res[1]))
edges = make([][]int, ne)
weights = make([]float64, ne)
case strings.HasPrefix(line, "<END OF METADATA>"):
reading_meta = false
}
return false
}
l := strings.Fields(line)
edges[k] = []int{io.Atoi(l[0]) - 1, io.Atoi(l[1]) - 1}
weights[k] = io.Atof(l[4])
k++
return false
})
} else {
_, dat, err := io.ReadTable(fname)
if err != nil {
chk.Panic("cannot read datafile\n%v", err)
}
ne = len(dat["from"]) // number of edges
edges = make([][]int, ne)
weights = make([]float64, ne)
for i := 0; i < ne; i++ {
edges[i] = []int{int(dat["from"][i]) - 1, int(dat["to"][i]) - 1}
weights[i] = dat["cost"][i]
}
}
// graph
var G Graph
G.Init(edges, weights, nil, nil)
return &G
}
// ReadSmat reads a smat matrix back
func ReadSmat(fn string) *Triplet {
var t Triplet
io.ReadLines(fn,
func(idx int, line string) (stop bool) {
r := strings.Fields(line)
if idx == 0 {
m, n, nnz := io.Atoi(r[0]), io.Atoi(r[1]), io.Atoi(r[2])
t.Init(m, n, nnz)
} else {
t.Put(io.Atoi(r[0]), io.Atoi(r[1]), io.Atof(r[2]))
}
return
})
return &t
}
// ReadLPfortran reads linear program from particular fortran file
// download LP files from here: http://users.clas.ufl.edu/hager/coap/format.html
// Output:
// A -- compressed-column sparse matrix where:
// Ap -- pointers to the begining of storage of column (size n+1)
// Ai -- row indices for each non zero entry (input, nnz A)
// Ax -- non zero entries (input, nnz A)
// b -- right hand side (input, size m)
// c -- objective vector (minimize, size n)
// l -- lower bounds on variables (size n)
// u -- upper bounds on variables (size n)
func ReadLPfortran(fn string) (A *la.CCMatrix, b, c, l, u []float64) {
// variables
var m int // number or rows (input)
var n int // number of columns (input)
var Ap []int // pointers to the begining of storage of column (size n+1)
var Ai []int // row indices for each non zero entry (input, nnz A)
var Ax []float64 // non zero entries (input, nnz A)
var z0 float64 // initial fixed value for objective
// auxiliary
reading_Ap := false
reading_Ai := false
reading_Ax := false
reading_b := false
reading_c := false
reading_z0 := false
reading_l := false
reading_u := false
atof := func(s string) float64 {
return io.Atof(strings.Replace(s, "D", "E", 1))
}
// read data
k := 0
io.ReadLines(fn, func(idx int, line string) (stop bool) {
if idx == 0 { // skip name
return
}
str := strings.Fields(line)
if idx == 1 { // read m and m
m, n = io.Atoi(str[0]), io.Atoi(str[1])
Ap = make([]int, n+1)
k = 0
reading_Ap = true
return
}
for _, s := range str {
if reading_Ap {
if k == n+1 {
reading_Ap = false
reading_Ai = true
nnz := Ap[n]
Ai = make([]int, nnz)
Ax = make([]float64, nnz)
b = make([]float64, m)
c = make([]float64, n)
l = make([]float64, n)
u = make([]float64, n)
k = 0
} else {
Ap[k] = io.Atoi(s) - 1 // subtract 1 because of Fortran indexing
}
}
if reading_Ai {
if k == Ap[n] {
reading_Ai = false
reading_Ax = true
k = 0
} else {
Ai[k] = io.Atoi(s) - 1 // subtract 1 because of Fortran indexing
}
}
if reading_Ax {
if k == Ap[n] {
reading_Ax = false
reading_b = true
k = 0
} else {
Ax[k] = atof(s)
}
}
if reading_b {
if k == m {
reading_b = false
reading_c = true
k = 0
} else {
b[k] = atof(s)
}
}
if reading_c {
if k == n {
reading_c = false
reading_z0 = true
k = 0
} else {
c[k] = atof(s)
}
}
if reading_z0 {
z0 = atof(s)
_ = z0
reading_z0 = false
reading_l = true
k = 0
return
}
if reading_l {
if k == n {
reading_l = false
reading_u = true
k = 0
} else {
l[k] = atof(s)
}
}
if reading_u {
if k == n {
reading_u = false
k = 0
} else {
u[k] = atof(s)
}
}
k++
}
return
})
// debug
if false {
io.Pforan("Ap = %v\n", Ap)
io.Pfcyan("Ai = %v\n", Ai)
io.Pfyel("Ax = %v\n", Ax)
io.Pf("b = %v\n", b)
io.Pforan("c = %v\n", c)
io.Pfcyan("l = %v\n", l)
io.Pfyel("u = %v\n", u)
}
// results
A = new(la.CCMatrix)
A.Set(m, n, Ap, Ai, Ax)
return
}