Read floating point numbers into a dynamically allocated while increasing the size of the array while reading the file
ifstream input("my-file.txt");
vector<float> myValues;

for (float f; input >> f; )
    myValues.push_back(f);

ifstream input("my-file.txt");
vector<float> myValues;

myValues.insert(myValues.begin(),
                istream_iterator<float>(input),
                istream_iterator<float>());

ifstream input("my-file.txt");
vector< vector<float> > myValues;

for (string line; getline(input, line); ) {
    stringstream lineStream(line);

    vector<float> thisLine;

    thisLine.insert(thisLine.begin(),
                    istream_iterator<float>(lineStream),
                    istream_iterator<float>());
    myValues.push_back(thisLine);
}