ma2D: Stratified bivariate robust local regression
Description
This function performs robust local regression of a variable z on predictor variables x and y, separately within values of a fourth variable g. It is used by maNorm2D for 2D spatial location normalization.
Usage
ma2D(x, y, z, g, w=NULL, subset=TRUE, span=0.4, ...)
Arguments
x
A numeric vector of predictor variables.
y
A numeric vector of predictor variables.
z
A numeric vector of responses.
g
Variables used to stratify the data.
w
An optional numeric vector of weights.
subset
A "logical" or "numeric" vector indicating the subset of points used to compute the fits.
span
The argument span which controls the degree of
smoothing in the loess function.
...
Misc arguments
Value
A numeric vector of fitted values.
Details
z is regressed on x and y, separately within values of g using the loess function.
References
S. Dudoit and Y. H. Yang. (2002). Bioconductor R packages for exploratory analysis and normalization of cDNA microarray data. In G. Parmigiani, E. S. Garrett, R. A. Irizarry and S. L. Zeger, editors, The Analysis of Gene Expression Data: Methods and Software, Springer, New York.