Converting string variable to float

[younes]

I would like to convert a string variable to float.

When acquiring data from text file, I use:

while( getline( ifs, temp ))
        {
          numberOfFeatures++;
            vecteur.clear();
            string::size_type stTemp = temp.find(separateur);
            number_descriptorEntries=0;
            while((stTemp != string::npos)&&(number_descriptorEntries<6))
            {
vecteur.push_back(temp.substr(0, stTemp-1));
                temp = temp.substr(stTemp + 1);
                stTemp = temp.find(separateur);            
            }           
            matrixe.push_back(vecteur);
            }
      return matrixe;
  }

the matrix that I obtain is of type vector<Vec> where Vec is a vector of strings.

I want to convert each element of matrixe to a float.

Thanks

Younes

[Little Bobby Tables]

i would use std::stringstream <sstream>

[younes]

I used the following code. But at the runtime I obtain some incoherences in the retrieved data.

MatrixXd Vision::clustering(int i){

const int ROWS=63;
const int COLS=10;
const int BUFFSIZE=100;
MatrixXd array(ROWS,COLS);

//int **array;
char buff[BUFFSIZE];

ifstream ifs("Brisc_db.txt");	
stringstream ss;

for(int row=0;row<ROWS-1;++row) {
ifs.getline(buff,BUFFSIZE);
ss<<buff;
for(int col=0;col<COLS-1;++col){
ss.getline(buff,5,',');
array(row,col)=atoi(buff);
// cout<<array(row,col)<<endl;
//**array=atoi(buff);
//(*array)++;
//cout<<array[row][col]<<"  ";
 ss<<"";
}
//array++;
ss.clear();
}
ifs.close();

return array;
}

[TwilightSpectre]

There is a function for converting from string to float: see std::stof:

// Example
std::string s1 = "1234.5678";
std::string s2 = "1.915e2";
std::string s3 = "-0.5e-5";

float f = std::stof(s1) + std::stof(s2) + std::stof(s3);

See http://www.cplusplus.com/reference/string/stof/