FullCIs.XY {BivRegBLS} | R Documentation |
Estimate the vertical and horizontal Ordinary least Square regressions, and several 'intermediate' Deming Regression (DR) and Bivariate Least Square (BLS), in a (X,Y) plot. The OLSv assumes no error on the X axis (λ=Infinity), while the OLSh assumes no error on the Y axis (λ=0). These two regressions are therefore 'extreme' regressions, while DR and BLS assume errors on both axes.
FullCIs.XY(data = NULL, xcol = 1, ycol = 2,
conf.level = 0.95, npoints = 1000, nlambdas = 13)
data |
a data set (data frame or matrix). |
xcol |
a numeric vector to specify the X column(s) or a character vector with the column names. |
ycol |
a numeric vector to specify the Y column(s) or a character vector with the column names. |
conf.level |
a numeric value for the confidence level (expressed between 0 and 1). |
npoints |
an integer (at least 10) for the number of points to smooth the hyperbolic curves. |
nlambdas |
an integer for the number of intermediate DR and BLS regressions (between the OLSv and OLSh). |
The data argument is mandatory. This function is especially useful for unreplicated data with unknown λ (the ratio of the measurement error variances), as it calculates all the potential solutions from OLSv to OLSh. The different estimated regression lines are provided with the different confidence intervals.
A CIs.XY class object, a list including the following elements:
Data.means |
a table with the X and Y data (means of the replicated data if replicated). |
Ellipses.CB |
an array of dimension [ |
Slopes |
a table ( |
Intercepts |
a table ( |
Joints |
a table ( |
Hyperbolic.intervals |
an array of dimension [npoints, 6 (X values, Y predictions, confidence interval and confidence bands),nlambdas+2] with the hyperbolic confidence intervals and confidence bands from OLSv to OLSh including |
Bernard G FRANCQ
Francq BG, Govaerts BB. Measurement methods comparison with errors-in-variables regressions. From horizontal to vertical OLS regression, review and new perspectives. Chemometrics and Intelligent Laboratory Systems, 2014; 134:123-139.
Francq BG, Govaerts BB. Hyperbolic confidence bands of errors-in-variables regression lines applied to method comparison studies. Journal de la Societe Francaise de Statistique 2014; 155(1):23-45.
library(BivRegBLS)
data(Aromatics)
res.full=FullCIs.XY(data=Aromatics,xcol=3,ycol=4)