func saveData(A *matrix.FloatMatrix) {
var fd *os.File
if fileName == "" {
fileName = testName + ".dat"
}
fd, err := os.Create(fileName)
if err != nil {
fmt.Fprintf(os.Stderr, "create error: %v\n", err)
return
}
io.WriteString(fd, A.ToString("%14e"))
fd.Close()
}