Compute Probabilities for Target Recognition
The hypergeometric distribution is used to infer if the number of anomalous sites along a traverse reliably reflect the presence of the dispersion pattern from a known mineral occurrence. The function displays the probability of the observed outcome could be due to chance alone.
gx.hypergeom(tt, aa, kk, xx)
tt |
total number of sites along a traverse. |
aa |
number of sites that a priori should be anomalous. |
kk |
total number of > threshold sites. |
xx |
number of the |
See Stanley (2003) for details, the examples below reproduce the results in Table 1 and Table 2.
Effectively, the hypothesis being tested is that the pattern of above threshold (see fences), sites coincides the the expected dispersion pattern from a known mineral occurrence. This requires that the geochemist uses knowledge of the dispersion processes active along the traverse, both chemical and mechanical, to predict an expected dispersion pattern.
Robert G. Garrett
Stanley, C.R., 2003. Statistical evaluation of anomaly recognition performance. Geochemistry: Exploration, Environment, Analaysis, 3(1):3-12.
## From Stanley (2003) Tables 1 and 2 gx.hypergeom(31, 10, 5, 3) gx.hypergeom(31, 10, 3, 2) gx.hypergeom(31, 10, 4, 3) gx.hypergeom(31, 10, 4, 4) gx.hypergeom(31, 10, 6, 5) gx.hypergeom(31, 10, 3, 3)
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