geometricmean {compositions}

The geometric mean

Description

Computes the geometric mean.

Usage

          geometricmean(x,...)
          geometricmeanRow(x,...)
          geometricmeanCol(x,...)
          gsi.geometricmean(x,...)
          gsi.geometricmeanRow(x,...)
          gsi.geometricmeanCol(x,...)
          

Arguments

x

a numeric vector or matrix of data

...

further arguments to compute the mean

Details

The geometric mean is defined as:

geometricmean(x) := \left( \prod_{i=1}^n x_i\right)^{1/n}

The geometric mean is actually computed by exp(mean(log(c(unclass(x))),...)).

Value

The geometric means of x as a whole (geometricmean), its rows (geometricmeanRow) or its columns (geometricmeanCol).

Missing Policy

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.

Author(s)

K.Gerald v.d. Boogaart http://www.stat.boogaart.de

See Also

mean.rplus

Examples

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)