The geometric mean
Computes the geometric mean.
geometricmean(x,...)
geometricmeanRow(x,...)
geometricmeanCol(x,...)
gsi.geometricmean(x,...)
gsi.geometricmeanRow(x,...)
gsi.geometricmeanCol(x,...)x |
a numeric vector or matrix of data |
... |
further arguments to compute the mean |
The geometric mean is defined as:
geometricmean(x) := \code{prod(x)^(1/length(x))}
The geometric mean is actually computed by
exp(mean(log(c(unclass(x))),...)).
The geometric means of x as a whole (geometricmean), its rows (geometricmeanRow) or its columns (geometricmeanCol).
The the first three functions take the geometric mean of all non-missing values. This is because they should yield a result in term of data analysis.
Contrarily, the gsi.* functions inherit the arithmetic IEEE policy of R through
exp(mean(log(c(unclass(x))),...)). Thus, NA codes a not available i.e.
not measured, NaN codes a below detection limit, and 0.0 codes a structural zero.
If any of the elements involved is 0, NA or NaN the result is of the same
type. Here 0 takes precedence over NA, and NA takes precedence
over NaN. For example, if a structural 0 appears, the geometric mean is 0
regardless of the presence of NaN's or NA's in the rest. Values below detection
limit become NaN's if they are coded as negative values.
K.Gerald v.d. Boogaart http://www.stat.boogaart.de
geometricmean(1:10) geometricmean(c(1,0,NA,NaN)) # 0 X <- matrix(c(1,NA,NaN,0,1,2,3,4),nrow=4) X geometricmeanRow(X) geometricmeanCol(X)
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