summary.ros {NADA}R Documentation

Summary and Plotting of Regression on Order Statistics models

Description

Generic implementations of summary and plotting functions for ROS models.

summary.ros provides the standard summary of the linear model. Has the option of producing the standard linear-model quality plots.

plot.ros constructs a probability plot representation of the ROS model.

abline.ros adds a line representing the linear regression model to an existing ROS prob-plot – For comparing two or more ROS models.

Usage

    ## S3 method for class 'ros':
    summary(object, plot=FALSE, ...) 
    ## S3 method for class 'ros':
    plot(x, plot.censored=FALSE, lm.line=TRUE, grid=TRUE, ylab="Value", pch=16, ...)
    ## S3 method for class 'ros':
    abline(a, ...)

Arguments

object A ROS model constructed using ros
plot Logical indicating whether the standard lm quality plots should be drawn.
x A ROS model constructed using ros
plot.censored A logical indicating if the modeled censored values should be plotted.
lm.line A logical indicating if the a line (abline) representing the linear regression model should be drawn on the plot.
grid A logical indicating if dotted lines are to be drawn at major axis division.
ylab A character string for the y-axis lable.
pch The numerical code of the plotting symbols for the uncensored data. See par
... Additional arguments passed to the generic method.
a A ROS model constructed using ros

Details

Author(s)

Lopaka(Rob) Lee <rclee@usgs.gov>

References

Lee and Helsel (in press) Statistical analysis of environmental data containing multiple detection limits: S-language software for regression on order statistics, Computers in Geoscience vol. X, pp. X-X

Lee and Helsel (in press) Baseline models of trace elements in major aquifers of the United States. Applied Geochemistry vol. X, pp. X-X.

Dennis R. Helsel (2004), Nondetects And Data Analasis: John Wiley and Sons, New York.

Dennis R. Helsel (1990), Less Than Obvious: Statistical Methods for, Environmental Science and Technology, vol.24, no. 12, pp. 1767-1774

Dennis R. Helsel and Timothy A. Cohn (1988), Estimation of descriptive statistics for multiply censored water quality data, Water Resources Research vol. 24, no. 12, pp.1997-2004

See Also

ros, predict.ros, quantile.ros, sd.ros, mean.ros, median.ros

Examples

    obs      = c(0.5,    0.5,   1.0,  1.5,   5.0,    10,   100)
    censored = c(TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE)

    myros = ros(obs, censored) 
    summary(myros, plot=TRUE) # Cycles through standard lm() plots

    plot(myros, plot.cen=TRUE) # Forms a prob-plot of the ROS model

    obs2      = c(0.5,    1.0,  1.5,   1.5,    10,   100,   200)
    censored2 = c(TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE)

    abline(ros(obs2, censored2)) # Draws this regression line on existing plot

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