FSA (version 0.8.11)

geomean: Calculates the geometric mean or geometric standard deviation.

Description

Calculates the geometric mean or standard deviation of a vector of numeric values.

Usage

geomean(x, na.rm = FALSE, zneg.rm = FALSE)
geosd(x, na.rm = FALSE, zneg.rm = FALSE)

Arguments

x

Vector of numeric values.

na.rm

Logical indicating whether to remove missing values or not.

zneg.rm

Logical indicating whether to ignore or remove zero or negative values found in x.

Value

A numeric value that is the geometric mean or geometric standard deviation of the numeric values in x.

Details

The geometric mean is computed by log transforming the raw data in x, computing the arithmetic mean of the transformed data, and back-transforming this mean to the geometric mean by exponentiating.

The geometric standard deviation is computed by log transforming the raw data in x, computing the arithmetic standard deviation of the transformed data, and back-transforming this standard deviation to the geometric standard deviation by exponentiating.

See Also

See geometric.mean in psych and Gmean for geometric mean calculators. See Gsd for geometric standard deviation calculators.

Examples

## generate random lognormal data
d <- rlnorm(500,meanlog=0,sdlog=1)
# d has a mean on log scale of 0; thus, gm should be exp(0)~=1
# d has a sd on log scale of 1; thus, gsd should be exp(1)~=2.7
geomean(d)
geosd(d)

## Demonstrate handling of zeroes and negative values
x <- seq(0,5)
# this will given an error
try(geomean(x))
# this will only give a warning, but might not be what you want
geomean(x,zneg.rm=TRUE)