How to read numbers from an ASCII file (C++)

Question

I need to read in data files which look like this:

* SZA: 10.00
 2.648  2.648  2.648  2.648  2.648  2.648  2.648  2.649  2.650  2.650
 2.652  2.653  2.652  2.653         


        

Answer 1

I would do something like this:

std::ifstream input("input.txt");
std::vector floats;
std::string header;
std::getline(input, header); // read in the "* SZA: 10.00" line
if(header_is_correct(header)) {
    float value;
    // while we could successfully read in a float from the file...
    while(input >> value) {
        // store it in the vector.
        floats.push_back(value);
    }
}

NOTE: header_is_correct(header) is just an example, you will need to implement any error checking for that first line manually there.