"fv"
from raw numerical data.
fv(x, argu = "r", ylab = NULL, valu, fmla = NULL, alim = NULL, labl =
names(x), desc = NULL, unitname = NULL, fname = NULL, yexp = ylab)x that contains
the values of the function argument.
NULL, or an R language expression
representing the mathematical name of the
function. See Details.
x that should be taken
as containing the function values, in cases where a single column
is required.
NULL, or a formula specifying the default
plotting behaviour. See Details.
x.
A vector of strings, with one entry for each column of x.
x.
A vector of strings, with one entry for each column of x.
ylab
more suitable for annotating an axis of the plot.
See Details.
"fv", see fv.object.
fv.object. The low-level function fv is used to create an object of
class "fv" from raw numerical data.
The data frame x contains the numerical data.
It should have one column
(typically but not necessarily named "r")
giving the values of the function argument for which
the function has been evaluated; and at least one other column,
containing the corresponding values of the function.
Typically there is more than one column of function values. These columns typically give the values of different versions or estimates of the same function, for example, different estimates of the $K$ function obtained using different edge corrections. However they may also contain the values of related functions such as the derivative or hazard rate.
argu specifies the name of the column of
x that contains the values of the function argument
(typically argu="r" but this is not compulsory).
valu specifies the name of another column
that contains the ‘recommended’ estimate of the function.
It will be used to provide function values in those situations where
a single column of data is required. For example,
envelope computes its simulation envelopes
using the recommended value of the summary function.
fmla specifies the default plotting behaviour.
It should be a formula, or a string that can be converted to a
formula. Variables in the formula are names of columns of x.
See plot.fv for the interpretation of this
formula.
alim specifies the recommended range of the
function argument. This is used in situations where statistical
theory or statistical practice indicates that the computed
estimates of the function are not trustworthy outside a certain
range of values of the function argument. By default,
plot.fv will restrict the plot to this range.
fname is a string giving the name of the function itself.
For example, the $K$ function would have fname="K".
ylab is a mathematical expression
for the function value, used when labelling an axis
of the plot, or when printing a description of the
function. It should be an R language object.
For example the $K$ function's mathematical name $K(r)$ is rendered
by ylab=substitute(K(r), NULL).
If yexp is present, then ylab will be
used only for printing, and yexp will be used for
annotating axes in a plot. (Otherwise yexp defaults to ylab).
For example the cross-type $K$ function
$K[1,2](r)$ is rendered by something like
ylab=substitute(Kcross[i,j](r), list(i=1,j=2))
and
yexp=substitute(Kcross[list(i,j)](r), list(i=1,j=2))
to get the most satisfactory behaviour.
labl is a character vector specifying plot labels
for each column of x. These labels will appear on the
plot axes (in non-default plots), legends and printed output.
Entries in labl
may contain the string "%s" which will be replaced
by fname. For example the border-corrected estimate
of the $K$ function has label "%sbord(r)" which
becomes "Kbord(r)".
desc is a character vector containing intelligible
explanations of each column of x. Entries in
desc may contain the string "%s" which will be replaced
by ylab. For example the border correction estimate of the
$K$ function has description "border correction estimate of %s".
plot.fv for plotting an "fv" object. See as.function.fv to convert an "fv" object
to an R function.
Use cbind.fv to combine several "fv" objects.
Use bind.fv to glue additional columns onto an existing
"fv" object.
Use range.fv to compute the range of $y$ values
for a function, and with.fv for more complicated
calculations.
The functions fvnames, fvnames<- allow the user to
use standard abbreviations to refer to columns of an "fv" object.
Undocumented functions for modifying an "fv" object
include tweak.fv.entry and rebadge.fv.
df <- data.frame(r=seq(0,5,by=0.1))
df <- transform(df, a=pi*r^2, b=3*r^2)
X <- fv(df, "r", substitute(A(r), NULL),
"a", cbind(a, b) ~ r,
alim=c(0,4),
labl=c("r", "%s[true](r)", "%s[approx](r)"),
desc=c("radius of circle",
"true area %s",
"rough area %s"),
fname="A")
X
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