| eval.parameters {RandomFields} | R Documentation |
eval.parameters provides an interactive menu on a X11 graphical device of R
eval.parameters(variable, entry, update, simulate, dev, create = TRUE,
col.rect = "red", col.bg = "blue", col.sep = "grey",
col.left = "red", col.mid = "white", col.right = "white",
col.line = "red", col.txt = "black",
cex=0.8, cex.i=cex, sep="-----", ...)
variable |
string. The name of the variable to be changed.
The name consist of $ and [[]] expression pointing
to sublists of a list. The complete list must be given by
name in ... |
entry |
A list of lists. See Details. |
update |
logical. If TRUE then simulate is called
after each interactive input. |
simulate |
function that is called if simulations are to
updated. The parameters must equal the variables given by
...; the function must return the complete list indicated by
variable. |
dev |
Before calling eval.parameters() split.screen
must have been called. dev gives the screen on which the
interactive menu should be plotted. |
create |
logical. If TRUE missing list elements of
variable are created. |
col.rect |
colour of the button for free input. |
col.bg |
colour of a interactive bar |
col.sep |
colour of the separating line |
col.left |
colour of preceding element |
col.mid |
colour for the message |
col.right |
colour of subsequent element |
col.line |
colour of the marking line in interactive bars of absolute choice. |
col.txt |
colour of headers |
cex |
font height of headers |
cex.i |
font height of text for elements |
sep |
style of added characters in separating line. |
... |
The input variables given by name;
the names may not start with a dot;
There the complete list to which variable refers must be
given. Further additional parameters for the function simulate.
|
eval.parameters shows a menu list on X11. Depending on the
mode of the variables the menu bars have a different appearance and
behave differently if the user clicks on the bar.
Most of the menu bars have a small rectangle on
the right hand side. If this rectangle is pressed the input of a
variable is expected in the xterm where R is run.
entry is a list of lists. Each list may contain the following
elements:
name : header for menu button if var is not
NULL; otherwise printed instead of a menu button
var :
NULL : if val=NULL then
it is a separating line in colour col.sep;
name is surrounded by sep; all other elements of
the list are ignored.
If val is a string then val is interpreted as a
function; a special string is "simulate", which entails the call of
the function simulate with the appropriate parameters.
variable. A special string "undo" will be
installed to undo things.
val :
function(d, v) gives the update for
var. If v is missing, a starting value (for
d=1/2) is expected. Otherwise, v is the current value
of var and d is the choice of the user,
a value in [0,1]
TRUE : logical bar.
FALSE : logical bar. The value for var is
negated before shown.
In the menu, the negative value for var is shown.
NULL : a string is read from the terminal inot var.
var is given then
this vector of strings is interpreted as belonging to a
categorical variable
1,...,length(val)
and var gives the number of the selected elements.
If var=NULL then val is interpreted as a function; a
special string is "simulate", which entails the call of
the function simulate with the appropriate parameters.
delta : logical.
In the menu bar absolute values are plotted if delta=FALSE
and increments otherwise. Only considered if val is a function.
cond : The menue points is shown only if the given
condition is satisfied. The condition must be expressed by named elements
of the list variable, see example.
col : colour that overwrites the standard colour for the
rectangle or the separating text.
update : logical. If not missing, its value overwrites
locally the value of the global parameter update.
... : additional parameters for simulate that overwrite
the values given in ... in the call of eval.parameters.
The first variable given in “...”, which is a list.
To this list the entry .history is added.
If the users enters ‘exit immediately’ at any point, the program
stops with an error message.
To the list given by variable the element .history
is added. .history is a list that contains the history
of the user input. Each element is a list where the first entry
is the number of the menu, the second and the third entries are the
former and the new value. Exception: for entries with character
val, the value of val is returned as second entry.
Consequently, the name .history should not be used for other
purposes in variable.
Further, any variable name given in ... must start with a letter.
Martin Schlather, martin.schlather@math.uni-goettingen.de http://www.stochastik.math.uni-goettingen.de/institute
## the following lines define a menu that does not make
## too much sense, but shows the various kinds of buttons
quadratic <- function(d, v, a, mini=0, maxi=Inf) {
d <- pmin(1, pmax(0, d)) - 0.5
d <- ((d>0) * 2 - 1) * d^2 * a * 4
if (missing(v)) d else pmax(mini, pmin(maxi, v + d))
}
simulate <- function(H, par) { ## not a serious example
print(c(H$x$var, par, runif(1)))
return(H) ## the function must return the first parameter
}
entry <- list(
list(name="Nonsense Menu"),
list(name="Simulate!", val="simulate", col="blue"),
list(name="show H", val="str(H)", col="blue"),
list(name="colx", var="colour",
val=c("red", "green", "blue", "brown")),
list(name="open", var="closed", val=FALSE, par=4.5),
list(name="modifying", var="modify", val=TRUE, par=5),
list(name="probability", var="probab", delta=FALSE,
val=function(d, v) pmin(1, pmax(0, d))),
list(name="variance", var="var", delta=TRUE,
val=function(d, v) quadratic(d, v, 10)),
list(name="name", var="name", par=3, cond="modify")
)
scr <- split.screen(rbind(c(0, 0.45, 0, 1), c(0.5, 1, 0, 1)))
## before proceeding make sure that both the screen and the xterm
## are completely visible
H <- list(modify=5, x=list()) # note that in this example eval.parameters
## will be called by by H$x, hence modify=5 will be left
## unchanged.
options(locatorBell=FALSE)
useraction("start.register") ## registring the user's input
str(eval.parameters("H$x", entry, simulate, update=TRUE, dev=scr[2],
H=H, par=17)) # do not forget to call by name
getactions()
## replay the user's input
useraction("replay")
str(eval.parameters("H$x", entry, simulate, update=TRUE, dev=scr[2],
H=H, par=17))