seawaveQ (version 1.0.0)

cenScatPlot: Scatter plot of water-quality data

Description

Function to generate a scatter plot that indicates censored and estimated water-quality concentrations.

Usage

cenScatPlot(data, datescol = "dates", pname,
    qwcols = c("R", "P"), site = "", xlabel = "",
    ylabel = "Concentration", legpos = "topright",
    legcex = 1, ...)

Arguments

data

is the dataset with columns that begin with P followed by alphanumeric characters indicating concentration data and columns that begin with R followed by alphanumeric characters that match those of the concentration data indicating qualification c

datescol

is the column label for the dates column.

pname

is the the column heading (paramenter name) for the particular water-quality constituent to be plotted (omit the the starting character, for example for sulfate data indicated by P00945, enter "00945").

qwcols

is a character vector with the beginning of the column headers for remarks code (default is R), and beginning of column headers for concentration data (default is P for parameter).

site

is a label for the plot title indicating the site where the water-quality samples were collected.

xlabel

is the label for the x-axis, defaults to no label.

ylabel

is the label for the y-axis.

legpos

is the position of the legend, see legend.

legcex

is a numerical value giving the amount by which the legend text and symbols should be magnified relative to the default, 1.

...

arguments to be passed to plot method.

Value

• a scatter plot

Details

This function uses the qualification, or remark, column associated with water-quality concentration values to indicate which samples are unqualified, which are estimated, and which are censored. A blank remark field or an "_" indicates that the concentration value is not qualified; an "E" indicates the values has been estimated; and a less than symbol, "

References

Oblinger Childress, C.J., Foreman, W.T., Connor, B.F., and Maloney, T.J., 1999, New reporting procedures based on long-term method detection levels and some considerations for interpretations of water-quality data provided by the U.S. Geological Survey: U.S. Geological Survey Open-File Report 99--193, 19 p. (Also available at http://water.usgs.gov/owq/OFR_99-193/index.html.)

Examples

data(swData)
# scatter plot of Simazine concentrations
cenScatPlot(IllRivValleyCty, pname="04035")
# scatter plot with many additional plotting arguments
par(las=1, tcl=0.5)
cenScatPlot(IllRivValleyCty, pname="04035",
            site="05586100 Illinois River at Valley City, IL",
            ylabel="Simazine concentration, in micrograms per liter",
            legcex=0.7, ylim=c(0,0.4), yaxs="i", cex.lab=0.9,
            cex.axis=0.9, xlim=c(as.Date("1996-01-01", "%Y-%m-%d"),
            as.Date("2012-01-01", "%Y-%m-%d")), xaxs="i", xaxt="n")
axdates<-c("1996-01-01", "2000-01-01", "2004-01-01", "2008-01-01",
           "2012-01-01")
axis(1, as.Date(axdates, "%Y-%m-%d"),
     labels=c("1996", "2000", "2004", "2008", "2012"), cex.axis=0.9)