rgr: anova2 – R documentation

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anova2

Analysis of Variance (ANOVA), Alternate Input

Description

Function to prepare data stored in alternate forms from that expected by function anova1 for its use. For further details see x in Arguments below.

Usage

anova2(x, xname = deparse(substitute(x)), log = FALSE, ifalt = FALSE)

Arguments

`x`	a column vector from a matrix or data frame, `x[1], ..., x[2*n]`. The default is that the first n members of the vector are the first measurements and the second n members are the duplicate measurements. If the measurements alternate, i.e. duplicate pair 1 measurement 1 followed by measurement 2, etc., set `ifalt = TRUE`.
`xname`	by default the character string for `x` is used for the title. An alternate title can be displayed with `xname = "text string"`, see Examples.
`log`	if a logarithmic transformation (base 10) of the data is required to meet homogeneity of variance considerations (i.e. severe heteroscedasticity) set `log = TRUE`. This is also advisable if the range of the observations exceeds 1.5 orders of magnitude.
`ifalt`	set `ifalt = TRUE` to accommodate alternating sets of paired observations.

Details

For further details see anova1.

If the data are as n duplicate pairs, x1 and x2, use function anova1.

Note

Any less than detection limit values represented by negative values, or zeros or other numeric codes representing blanks in the data, must be removed prior to executing this function, see ltdl.fix.df.

Author(s)

Robert G. Garrett

Examples

## Make test data available
data(ms.data2)
attach(ms.data2)

## Undertake an ANOVA for duplicate measurements on rock samples
anova2(MS, log = TRUE, 
	xname = "Duplicate measurements of Magnetic Susceptibility")

## Detach test data
detach(ms.data2)

## Make test data available
data(ms.data3)
attach(ms.data3)

## Undertake an ANOVA for duplicate measurements on rock samples
anova2(MS, log = TRUE, ifalt = TRUE, 
	xname = "Duplicate measurements of Magnetic Susceptibility")

## Detach test data
detach(ms.data3)

rgr

Applied Geochemistry EDA

v1.1.15

GPL-2

Authors

Robert G. Garrett

Initial release

2018-03-05