| 137 | |
| 138 | |
| 139 | float _vector_stdev(std::vector<float>& x) |
| 140 | { |
| 141 | float sum, mean, accum, stdev; |
| 142 | sum = std::accumulate(std::begin(x), std::end(x), 0.0); |
| 143 | mean = sum / x.size(); |
| 144 | accum = 0.0; |
| 145 | std::for_each (std::begin(x), std::end(x), [&](const float d) { |
| 146 | accum += (d - mean) * (d - mean); |
| 147 | }); |
| 148 | stdev = sqrt(accum / (x.size() - 1)); |
| 149 | return stdev; |
| 150 | } |
| 151 | |
| 152 | |
| 153 | int main(int argc, char **argv) |