abs_stdapd: Absolute values of gradients (apd's) of kernel regressions of x on y when
both x and y are standardized.
Description
1) standardize the data to force mean zero and variance unity, 2) kernel
regress x on y, with the option `gradients = TRUE' and finally 3) compute
the absolute values of gradients
Usage
abs_stdapd(x, y)
Arguments
x
vector of data on the dependent variable
y
data on the regressors which can be a matrix
Value
Absolute values of kernel regression gradients are returned after
standardizing the data on both sides so that the magnitudes of amorphous
partial derivatives (apd's) are comparable between regression of x on y on
the one hand and regression of y on x on the other.
Details
The first argument is assumed to be the dependent variable. If
abs_stdapd(x,y) is used, you are regressing x on y (not the usual y
on x). The regressors can be a matrix with 2 or more columns. The missing values
are suitably ignored by the standardization.