transforms: Transforms

Description Usage Arguments Details Value References Examples

Description

Transformations appropriate for ecological data.

Usage

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Arguments

x

vector or array of values to transform

...

further arguments passed to other methods

Details

asin_sqrt = Arc-sine square root transform:
Appropriate for vegetation cover and other proportion data. Forces data to 0-1 scale if any original values were outside this range. Follows pg. 69 of McCune & Grace (2002).

genlogtrans = Generalized log-transform:
Log transform that properly handles zeros and very small values. Preserves original order of magnitudes while accounting for values = 0 and << 1. Follows pg. 69 of McCune & Grace (2002).

standardize = Range standardize:
Standardizes data to 0-1 scale based on min/max values.

Value

Values on the modified scale.

References

McCune, B., and J. B. Grace. 2002. Analysis of Ecological Communities. MjM Software, Gleneden Beach, Oregon, USA. 304 pp.

Examples

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set.seed(21)
x  <- rnorm(99, 50, 20)
x1 <- asin_sqrt(x)
x2 <- genlogtrans(x)
x3 <- standardize(x)
par(mfrow=c(1,3))
plot(x, x1)
plot(x, x2)
plot(x, x3)
par(mfrow=c(1,1))

phytomosaic/ecole documentation built on May 6, 2019, 3:45 p.m.