()
| 231 | } |
| 232 | |
| 233 | @Override |
| 234 | public double variance() |
| 235 | { |
| 236 | if(varianceCache != null) |
| 237 | return varianceCache; |
| 238 | double mu = mean(); |
| 239 | double tmp = 0; |
| 240 | |
| 241 | double N = length(); |
| 242 | |
| 243 | |
| 244 | for(int i = startIndex; i < endIndex; i++) |
| 245 | tmp += pow(array[i]-mu, 2)/N; |
| 246 | |
| 247 | return (varianceCache = tmp); |
| 248 | } |
| 249 | |
| 250 | @Override |
| 251 | public double dot(Vec v) |