sm.sigma(x, y, diff.ord=2)
x
| a vector of covariate values. |
y
| a vector of response values. |
diff.ord
| an integer defining the degree of differencing to be applied in the esimtation process. When this argument is set to 1, the method of Rice, based on the squared differences of pairs of neighbouring observations, is used. When the argument is set to 2, the method of Gasser, Sroka and Jennen-Steinmetz, based on differences between each observation and a linear interplotation from its two neighbours, is used. |
sm.regression
, sm.ancova
x <- runif(100,-2, 2) y <- x^2 + rnorm(50) sm.sigma(x, y)