range2sigma {shotGroups} | R Documentation |
Estimate Rayleigh sigma based on range statistics
Description
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.
Usage
range2sigma(x, stat="ES", n=5, nGroups=1, CIlevel=0.95,
collapse=TRUE, dstTarget, conversion)
Arguments
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 |
Details
Based on the lookup table DFdistr
with results form 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")
.
Value
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. |
References
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.
See Also
DFdistr
,
range2CEP
,
efficiency
,
getRayParam
,
getMaxPairDist
,
getBoundingBox
Examples
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)