move.1: Maintenance of Variance Extension, Type 1

In USGS-R/smwrStats: R functions to support statistical methods in water resources

Maintenance of Variance Extension, Type 1

Description

Calculates the Maintenance Of Variance Extension, Type 1 (MOVE.1) for record extension by fitting a Line of Organic Correlation (LOC) regression model.

Usage

move.1(formula, data, subset, na.action, distribution = "normal")

Arguments

formula	a formula object with the response variable on the left of the ~ operator and a single explantory variable on the right.
data	the data frame containing the variables named in formula.
subset	an optional vector specifying a subset of observations to be used in the fitting process.
na.action	a function that indicates what should happen when the data contain missing values (NAs). The default is set by the na.action setting of options and is na.fail if that is unset. Ohter possible options include na.exclude and na.omit.
distribution	either "normal," "lognormal," or "commonlog" indicating nature of the bivariate distribution, See Details.

Details

If distribution is "normal," then the data in x and y are assumed to have a bivariate normal distribution. Otherwise, they are assumed to have a bivariate log-normal distribution and a logarithmic transform is applied to both x and y before analysis. The natural logarithm is used if distribution is "lognormal" and the commmon logarithm is used if distribution is "commonlog."

Value

An object of class "move.1" having these components:

coefficients	the intercept and slope of the line describing the fit.
na.action	a character string indicating the special handling of NAs.
R	Pearson's correlation coefficient.
call	the matched call to move.1.
fitted.values	the fitted LOC values for the response.
residuals	a 2-column matrix containing the signed distance from the predicted to to the corresponding y and x values.
x	the (possibly transformed) values for x.
y	the (possibly transformed) values for y.
x.stats	the mean and standard deviation of the (possibly transformed) values for x.
y.stats	the mean and standard deviation of the (possibly transformed) values for y.
var.names	the names of y and x.
model	the model frame.

Note

Objects of class "move.1" have print, predict, and plot methods.

References

Hirsch, R.M., 1982, A comparison of four streamflow record extension techniques: Water Resources Research, v. 18, p. 1081–1088.

See Also

predict.move.1, plot.move.1

Examples

library(smwrData)
data(IonBalance)
# Build model for non missing Alkalinity
IB.move <- move.1(Anion_sum ~ Cation_sum, data=IonBalance, subset=abs(Pct_Diff) < 10)
print(IB.move)

USGS-R/smwrStats documentation built on Oct. 11, 2022, 6:15 a.m.