spatialEco (version 0.1-7)

loess.ci: Loess with confidence intervals

Description

Calculates a local polynomial regression fit with associated confidence intervals

Usage

loess.ci(y, x, p = 0.95, plot = FALSE, ...)

Arguments

y

Dependent variable, vector

x

Independent variable, vector

p

Percent confidence intervals (default is 0.95)

plot

Plot the fit and confidence intervals

...

Arguments passed to loess

Value

A list object with: loess Predicted values se Estimated standard error for each predicted value lci Lower confidence interval uci Upper confidence interval df Estimated degrees of freedom rs Residual scale of residuals used in computing the standard errors

References

W. S. Cleveland, E. Grosse and W. M. Shyu (1992) Local regression models. Chapter 8 of Statistical Models in S eds J.M. Chambers and T.J. Hastie, Wadsworth & Brooks/Cole.

Examples

 x <- seq(-20, 20, 0.1)
 y <- sin(x)/x + rnorm(length(x), sd=0.03)
 p <- which(y == "NaN")
   y <- y[-p]	
   x <- x[-p]
 
 par(mfrow=c(2,2))  
 lci <- loess.ci(y, x, plot=TRUE, span=0.10)
 lci <- loess.ci(y, x, plot=TRUE, span=0.30)
 lci <- loess.ci(y, x, plot=TRUE, span=0.50)
 lci <- loess.ci(y, x, plot=TRUE, span=0.80)