| MethComp {MethComp} | R Documentation |
Takes the results from BA.est, AltReg
or MCmcmc and returns a MethComp object,
suitable for displaying the relationship between methods in print
pr graphic form.
MethComp(obj)
## S3 method for class 'MethComp':
print(x, digits=4, ... )
## S3 method for class 'MethComp':
plot(x,
wh.cmp = 1:2,
pl.type = "conv",
axlim = range(x$data$y,na.rm=TRUE),
points = FALSE,
grid = TRUE,
N.grid = 10,
col.grid = grey(0.9),
col.lines = "black",
eqn = pl.type=="conv" & is.null(attr(x,"Transform")),
digits = 1,
... )
## S3 method for class 'MethComp':
lines(x,
wh.cmp = getOption("MethComp.wh.cmp"),
pl.type = getOption("MethComp.pl.type"),
axlim = par("usr")[1:2],
col.lines = "black",
... )
## S3 method for class 'MethComp':
points(x,
wh.cmp = getOption("MethComp.wh.cmp"),
pl.type = getOption("MethComp.pl.type"),
... )
obj |
A MethComp or MCmcmc object. |
x |
A MethComp object. |
digits |
How many digits should be used when displaying conversion equations and variance componenets. |
wh.cmp |
Numeric. Which methods should be plotted. |
pl.type |
Character. If "conv" it will be a plot of two methods against each other, otherwise it will be a plot of the 2nd minus the 1st versus the average; a Bland-Altman type plot. |
axlim |
The extent of the axes. |
points |
Logical. Should the points be included in the plot. |
grid |
Logical. Should there be a grid? |
N.grid |
Numeric. How many gridlines? If a vector of length>1, it will be taken as the position of the gridlines. |
col.grid |
Color of the gridlines. |
col.lines |
Color of the conversion lines. |
eqn |
Logical. Should the conversion equation be printed on the plot. |
... |
Further arguments. |
Using MethComp on the results from BA.est or
AltReg is not necessary, as these two functions already return
objetcs of class MethComp.
plot.MethComp plots the conversion function with prediction limits. It also
sets the options "MethComp.wh.cmp" indicating which two methods are
plotted and "MethComp.pl.type" indicating whether a plot of methods
against each other or a Bland-Altman type plot of differences versus averages.
lines.MethComp and points.MethComp adds conversion lines with
prediction limits and points to a plot.
MethComp returns a MethComp object, which is a list with three
elements, Conv, a three-way array giving the linear conversion equations
between methods, VarComp, a two-way array classified by methods and
variance components and data, a copy of the original Meth
object supplied.
A MethComp object has an attribute Transform,
which is either NULL, or a named list with elements trans and inv,
both of which are functions. The first is the transformation applied
to measurements before analysis; the results are all given on the transformed
scale. The second is the inverse transformation; this is only used when plotting
the resulting relationship between methods.
The methods return nothing.
Bendix Carstensen, Steno Diabetes Center, bxc@steno.dk.
data( ox ) BA.ox <- BA.est( ox, linked=TRUE ) print( BA.ox ) AR.ox <- AltReg( ox, linked=TRUE ) print( AR.ox )