Search results
Results From The WOW.Com Content Network
Excel graph of the difference between two evaluations of the smallest root of a quadratic: direct evaluation using the quadratic formula (accurate at smaller b) and an approximation for widely spaced roots (accurate for larger b). The difference reaches a minimum at the large dots, and round-off causes squiggles in the curves beyond this minimum.
The earliest reference to a similar formula ... a better measure of relative accuracy can be obtained based on the log of the accuracy ... J. S. (1985) Long-range ...
CEP is not a good measure of accuracy when this distribution behavior is not met. Munitions may also have larger standard deviation of range errors than the standard deviation of azimuth (deflection) errors, resulting in an elliptical confidence region. Munition samples may not be exactly on target, that is, the mean vector will not be (0,0).
This little-known but serious issue can be overcome by using an accuracy measure based on the logarithm of the accuracy ratio (the ratio of the predicted to actual value), given by (). This approach leads to superior statistical properties and also leads to predictions which can be interpreted in terms of the geometric mean.
In a classification task, the precision for a class is the number of true positives (i.e. the number of items correctly labelled as belonging to the positive class) divided by the total number of elements labelled as belonging to the positive class (i.e. the sum of true positives and false positives, which are items incorrectly labelled as belonging to the class).
This is known as a scale-dependent accuracy measure and therefore cannot be used to make comparisons ... This optimization-based definition of the median is ...
Precision and recall. In statistical analysis of binary classification and information retrieval systems, the F-score or F-measure is a measure of predictive performance. It is calculated from the precision and recall of the test, where the precision is the number of true positive results divided by the number of all samples predicted to be positive, including those not identified correctly ...
Range Expected fraction of population inside range Expected fraction of population outside range Approx. expected frequency outside range Approx. frequency outside range for daily event μ ± 0.5σ: 0.382 924 922 548 026: 0.6171 = 61.71 % 3 in 5 Four or five times a week μ ± σ: 0.682 689 492 137 086 [5] 0.3173 = 31.73 % 1 in 3 Twice or ...