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如何将文本文件的每一行分配给一个新的向量?

fstream text-files c++

Spandyie · 技术社区 · 8 年前

vector<float> ?

(0.165334,0) (0.166524,-0.0136064) (-0.144899,0.0207161)
(0.205171,0) (0.205084,-0.0139042) (-0.205263,0.0262445)
(0.216684,0) (0.215388,-0.0131107) (-0.193696,0.0251303)
(0.220137,0) (0.218849,-0.0135667) (-0.194153,0.025175)

这是我到目前为止得到的,但这段代码将数据作为字符串加载。我想将最终数据加载为 vector<vector<float>> ?

vector<vector<string> > input;    
ifstream fileFFT(Filename.c_str());
string line;
while(getline(fileFFT, line)){
    if(line.empty()){
        continue;
    }

    stringstream row(line);
    vector<string> values((istream_iterator<string>(row)),(istream_iterator<string>()));       //end

    input.push_back(values);

}

2 回复 | 直到 8 年前

Thomas Matthews 8 年前

以下是让您开始学习的内容:

class Point
{
public:
  double x;
  double y;
  friend std::istream& operator>>(std::istream& input, Point& p);
};

std::istream& operator>>(std::istream& input, Point& p)
{
  char c;
  input >> c; // Read open parenthesis
  input >> p.x;
  input >> c; // Read comma
  input >> p.y;
  input >> c; // Read closing parenthesis
  return input;
};

//...
std::string row_text;
std::vector<std::vector<Point>> matrix;
while (std::getline(my_file, row_text))
{
  std::vector<Point> row;
  std::istringstream(row_text);
  Point p;
  while (row_text >> p)
  {
    row.push_back(p);
  }
  matrix.push_back(row);
}

我创建了一个 Point

我也超载了 operator>> 使阅读成为 指向

循环读数为1 或文本行,然后创建 指向

Remy Lebeau 8 年前

你已经有一半的答案了-使用 std::getline() 阅读每一行,然后使用 std::(i)stringstream

std::istream_iterator ,我会这样做:

typedef std::pair<float, float> SensorValue;
typedef std::vector<SensorValue> SensorValues;

std::istream& operator>>(std::istream &in, SensorValue &out)
{
    float f1, f2;
    char ch1, ch2, ch3;

    if (in >> ch1 >> f1 >> ch2 >> f2 >> ch3)
    {
        if ((ch1 == '(') && (ch2 == ',') && (ch3 == ')'))
            out = std::make_pair(f1, f2);
        else
            in.setstate(std::ios_base::failbit);
    }

    return in;
}

...

std::vector<SensorValues> input;

std::ifstream fileFFT(Filename.c_str());
std::string line;

while (std::getline(fileFFT, line))
{
    if (line.empty())
        continue;

    std::istringstream row(line);

    SensorValues values;
    std::copy(std::istream_iterator<SensorValue>(row), std::istream_iterator<SensorValue>(), std::back_inserter(values));

    input.push_back(values);
}