range2sigma | R Documentation |
Estimate the Rayleigh sigma parameter based on range statistics like extreme spread, figure of merit, or the bounding box diagonal. This function assumes a circular bivariate normal shot distribution with 0 mean.
range2sigma(x, stat="ES", n, nGroups,
CIlevel=0.95, collapse=TRUE, dstTarget, conversion)
x |
a numerical vector with values for extreme spread (ES), figure of merit (FoM), or the diagonal of the bounding box (D). |
stat |
a character vector with elements |
n |
integer between 2 and 100. Number of shots in each group. |
nGroups |
integer between 1 and 10. Number of groups when |
CIlevel |
confidence level (coverage probability) for the Rayleigh sigma confidence interval. If one of |
collapse |
logical: should the list with CIs be simplified if possible? |
dstTarget |
a numerical value giving the distance to the target - used in MOA calculation. See |
conversion |
how to convert the measurement unit for distance to target to that of the (x,y)-coordinates in MOA calculation. Example |
Based on the lookup table DFdistr
with results from a Monte Carlo simulation. If the value of n
is not among those simulated (but is less than 100), a monotonic spline interpolation between the neighboring simulated values of the statistic's coefficient of variation is used.
For conversion to the circular error probable, see range2CEP
.
Details for the calculation can be found under
http://ballistipedia.com/index.php?title=Range_Statistics
If package shiny
is installed, an interactive web app for this functionality can be run with runGUI("range")
.
A list with the calculated values for sigma in one component, and the corresponding CIs in the other component.
sigma |
The calculated values for sigma in the original measurement unit as well as in angular size measures. |
sigmaCI |
The calculated CIs for sigma in the original measurement unit as well as in angular size measures. |
Taylor, M. S., & Grubbs, F. E. (1975). Approximate Probability Distributions for the Extreme Spread (BRL-MR-2438). Aberdeen Proving Ground, MD: U.S. Ballistic Research Laboratory.
DFdistr
,
range2CEP
,
efficiency
,
getRayParam
,
getMaxPairDist
,
getBoundingBox
es <- getMaxPairDist(DFscar17)$d
fom <- getBoundingBox(DFscar17)$FoM
d <- getBoundingBox(DFscar17)$diag
range2sigma(c(es, fom, d), stat=c("ES", "FoM", "D"),
n=nrow(DFscar17), nGroups=1, CIlevel=0.9)
# compare with Rayleigh sigma estimate from using
# (x,y)-coordinates of all shots
getRayParam(DFscar17, level=0.9)
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