mtklein | 90c471e | 2014-06-16 14:04:32 -0700 | [diff] [blame] | 1 | #ifndef Stats_DEFINED |
| 2 | #define Stats_DEFINED |
| 3 | |
mtklein | 40b32be | 2014-07-09 08:46:49 -0700 | [diff] [blame^] | 4 | #include "SkTSort.h" |
| 5 | |
mtklein | 90c471e | 2014-06-16 14:04:32 -0700 | [diff] [blame] | 6 | struct Stats { |
| 7 | Stats(const double samples[], int n) { |
| 8 | min = samples[0]; |
| 9 | max = samples[0]; |
| 10 | for (int i = 0; i < n; i++) { |
| 11 | if (samples[i] < min) { min = samples[i]; } |
| 12 | if (samples[i] > max) { max = samples[i]; } |
| 13 | } |
| 14 | |
| 15 | double sum = 0.0; |
| 16 | for (int i = 0 ; i < n; i++) { |
| 17 | sum += samples[i]; |
| 18 | } |
| 19 | mean = sum / n; |
| 20 | |
| 21 | double err = 0.0; |
| 22 | for (int i = 0 ; i < n; i++) { |
| 23 | err += (samples[i] - mean) * (samples[i] - mean); |
| 24 | } |
| 25 | var = err / (n-1); |
mtklein | 40b32be | 2014-07-09 08:46:49 -0700 | [diff] [blame^] | 26 | |
| 27 | SkAutoTMalloc<double> sorted(n); |
| 28 | memcpy(sorted.get(), samples, n * sizeof(double)); |
| 29 | SkTQSort(sorted.get(), sorted.get() + n - 1); |
| 30 | median = sorted[n/2]; |
mtklein | 90c471e | 2014-06-16 14:04:32 -0700 | [diff] [blame] | 31 | } |
| 32 | |
| 33 | double min; |
| 34 | double max; |
| 35 | double mean; // Estimate of population mean. |
| 36 | double var; // Estimate of population variance. |
mtklein | 40b32be | 2014-07-09 08:46:49 -0700 | [diff] [blame^] | 37 | double median; |
mtklein | 90c471e | 2014-06-16 14:04:32 -0700 | [diff] [blame] | 38 | }; |
| 39 | |
| 40 | #endif//Stats_DEFINED |