anova2: Analysis of Variance (ANOVA), Alternate Input

In rgr: Applied Geochemistry EDA

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

See Also

anova1, ltdl.fix.df

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)

Example output

Loading required package: MASS
Loading required package: fastICA

 Combined Sampling and Analytical, or Analytical Variability, Study, 
 Utilizes Field Sampling or Laboratory Duplicates.  In ANOVA Tables, 
 the variability: 
   Between would be between sampling sites or analysed samples, and 
   Within would be at sampling sites or due to duplicate analyses

 Data have been Log10 transformed for the ANOVA

 Two-Way Random Effects Model for Duplicate measurements of Magnetic Susceptibility 
 Source		  SS		df	  MS		  F	 Prob 
 Between	 37.272 	 15 	 2.4848 		 5447.94 	 0.0106 
 Within		 0.018874 		 1 	 0.018874 		 41.38 	 0 
 Residual	 0.0068415 		 15 	 0.0004561 
 Total		 37.298 	 31 	 1.2032

 One-Way Random Effects Model for Duplicate measurements of Magnetic Susceptibility 
 Source		  SS		df	  MS		  F	 Prob 
 Between	 37.272 	 15 	 2.4848 		 1546.06 	 0 
 Within		 0.025715 		 16 	 0.0016072 
 Total		 37.298 	 31 	 1.2032

 Source		  MS		Var Comp	 %age 
 Between	 2.4848 		 1.2416 		 99.9 
 Within		 0.0016072 		 0.0016072 		 0.1 
				 1.2432

 Summary Statistics for Duplicate measurements of Magnetic Susceptibility 
 Grand Mean =	 1.0064 		 Variance =	 1.2032 
 'Error' S^2 =	 0.0016072 		 Std. Dev. =	 0.04009 
 'Error' RSD% =	 4 
 Miesch's V = 	 772.53 		 Vm = 		 1545.06 


 Combined Sampling and Analytical, or Analytical Variability, Study, 
 Utilizes Field Sampling or Laboratory Duplicates.  In ANOVA Tables, 
 the variability: 
   Between would be between sampling sites or analysed samples, and 
   Within would be at sampling sites or due to duplicate analyses

 Data have been Log10 transformed for the ANOVA

 Two-Way Random Effects Model for Duplicate measurements of Magnetic Susceptibility 
 Source		  SS		df	  MS		  F	 Prob 
 Between	 37.272 	 15 	 2.4848 		 5447.94 	 0.0106 
 Within		 0.018874 		 1 	 0.018874 		 41.38 	 0 
 Residual	 0.0068415 		 15 	 0.0004561 
 Total		 37.298 	 31 	 1.2032

 One-Way Random Effects Model for Duplicate measurements of Magnetic Susceptibility 
 Source		  SS		df	  MS		  F	 Prob 
 Between	 37.272 	 15 	 2.4848 		 1546.06 	 0 
 Within		 0.025715 		 16 	 0.0016072 
 Total		 37.298 	 31 	 1.2032

 Source		  MS		Var Comp	 %age 
 Between	 2.4848 		 1.2416 		 99.9 
 Within		 0.0016072 		 0.0016072 		 0.1 
				 1.2432

 Summary Statistics for Duplicate measurements of Magnetic Susceptibility 
 Grand Mean =	 1.0064 		 Variance =	 1.2032 
 'Error' S^2 =	 0.0016072 		 Std. Dev. =	 0.04009 
 'Error' RSD% =	 4 
 Miesch's V = 	 772.53 		 Vm = 		 1545.06 

rgr documentation built on May 2, 2019, 6:09 a.m.