plot.threshpt: Plots from a threshpt Object

In HEAT: Health Effects of Air Pollution and Temperature (HEAT)

Description

Following four plots from a fitted threshpt object are provided:
Plot 1: plot for a response variable on the natural cubic spline of a exposure variable
Plot 2: plot for fitted response values with other mean covariates and 95% confidence intervals
Plot 3: plot for fitted response values
Plot 4: deviance by threshold point plot

Usage

## S3 method for class 'threshpt'
plot(x, select = NULL, se = T, expdf = 4, 
xlim = NULL, ylim = NULL, xaxt = NULL, yaxt = NULL, 
col.value = NULL, col.preval = NULL, col.ci = NULL, col.vline = NULL,
lwd = NULL, pch = NULL, pch.preval = NULL, main = NULL, xlab = NULL, ylab = NULL, ...)

Arguments

x	A fitted threshpt object produced by threshpt()
select	Select a plot type
se	When TRUE (default) upper and lower confidence interval lines are added to the plot 1 and 4. When FALSE, otherwise.
expdf	Degree of freedom of natural cubic spline function for the main exposure variable in plot 1; default value is four.
xlim	The x limits of the plot.
ylim	The y limits of the plot.
xaxt	A character which specifies the x axis type.
yaxt	A character which specifies the y axis type.
col.value	The color of main values or line in all kind of plot.
col.preval	The color of fitted value in plot 3.
col.ci	The color of confidence interval lines in plot 1 and 3.
col.vline	The color of vertical line that represents a optimum threshold in plot 2, 3 and 4.
lwd	Line width for plot 1
pch	Either an integer specifying a symbol or a single character to be used in plotting points in plot 2 and 3.
pch.preval	Either an integer specifying a symbol or a single character to be used in plotting fitted values in plot 3.
main	Overall title of the plot.
xlab	A title for the x axis of the plot
ylab	A title for the y axis of the plot
...	Not used.

Value

Generated four kind of plots from a fitted threshpt object

Author(s)

Youn-Hee Lim, Il-Sang Ohn, and Ho Kim

Examples

# read the Seoul data set and create lag variables
data(mort)
seoul = read6city(mort, 11)
seoul_lag = lagdata(seoul, c("meantemp", "mintemp", "meanpm10", "meanhumi"), 5)

# find a optimal threshold and conduct piecewise linear regression
mythresh = threshpt(nonacc ~ meantemp_m3 + meanpm10_m2 +  meanhumi + ns(sn, 4*10) + factor(dow), 
			     expvar = "meantemp_m3", family = "poisson", data = seoul_lag,
			     startrng = 23, endrng = 33, searchunit = 0.2)

# obtain plots
plot(mythresh, select = 1, se = TRUE, expdf=8, col.value = "blue", col.ci = "light blue")
plot(mythresh, select = 2, se = FALSE, col.vline = "orange")
plot(mythresh, select = 3, pch = 1, pch.preval = 2)
plot(mythresh, select = 4)

HEAT documentation built on May 29, 2017, 10:52 a.m.