| Ask {car} | R Documentation |
Ask allows you to change the argument to a function interactively.
It is meant to be used, in lieu of a graphical control such as a slidebar,
to adjust plotting parameters, which are
most naturally passed as the argument to an anonymous function that sets
up the plot.
Ask(arg, fun, ...)
arg |
argument to fun to change. By specifying a vector of values,
you can change several parameters via an argument to an anonymous function. |
fun |
function to call; often an anonymous function that sets up a call to plotting functions. |
... |
other arguments to fun; not necessary if fun
is an anonymous function. |
Ask repeatedly prompts in the R Console for the value of arg.
To exit, enter a blank line.
Ask returns invisibly the value of the last call to fun;
usually this will be NULL, and in any event is probably not of
interest. If it is, use print(Ask(arg, fun, ...)).
John Fox jfox@mcmaster.ca
## Not run:
attach(UN)
# enter the power-transformation parameter
# start with 1
Ask(p, function(p) qq.plot(box.cox(gdp, p),
ylab=paste("transformed gdp, power =",p)))
# enter an expression that evaluates to a 2-vector
# of powers; e.g., start with c(1,1); then interactively
# identify points in each plot
Ask(p, function(p) scatterplot(box.cox(gdp,p[1]),
box.cox(infant.mortality, p[2]),
xlab=paste("transformed GDP/capita, power =",p[1]),
ylab=paste("transformed infant mortality, power =",p[2]),
labels=rownames(UN)))
## End(Not run)