berryFunctions (version 1.4)

owa: overwrite argument lists passed to functions

Description

Can be used in functions that give defaults for several argument lists that are each passed to different functions. Some of the defaults can be overwritten, some should be left unchanged, some are aditionally specified by users. owa combines everything accordingly.

Usage

owa(d, a, u=NA)

Arguments

d

Default arguments

a

Arguments specified by user

u

names of Unchangeable arguments (that can not be overwritten). DEFAULT: NA

Value

• Always a list, disregarding list/vector mode of input

Details

None

References

http://stackoverflow.com/questions/3057341 http://stackoverflow.com/questions/5890576 http://stackoverflow.com/questions/4124900 http://stackoverflow.com/questions/16774946

Examples

d <- list(col="gray", lty=1, wachs=1:6, bb=42)
a <- list(lty=3, lwd=2, wachs="A", bb=16)

owa(d, a, u=c("bb", "wachs"))
owa(d, NULL, u=c("bb", "wachs")) # NULL is a good default for argument lists
owa(d, c(HH=2, BBB=3) ) # vectors and lists all converted to lists


# An example of how to code (as in funnelPlot or mReg):
# Why we want to do this:
testfun <- function(...) {plot(7:9, ...) ; legend("top", "Text hier", ...)}
testfun()
testfun(type="o") # legend doesn't have the argument 'type'!

# How we do this:
testfun <- function(data=7:9, legarg=NULL, plotarg=NULL)
   {
   # defaults for plot and legend:
   plot_def <- list(x=0.5*data, col="red", cex=2, lty=2, type="o")
   leg_def <- list(x="top", lty=2, legend="Default text here")
   # combine defaults and user specified into final argument list
   plot_fin <- owa(d=plot_def, a=plotarg, u=c("col", "lty"))
   leg_fin <- owa(d=leg_def, a=legarg, u="lty")
   # Execute single functions that each have their own arguments:
   do.call(  plot, args=plot_fin)
   do.call(legend, args=leg_fin)
   }

testfun()
testfun(plotarg=list(type="l", col="blue") )
# color is silently ignored, as it is defined as unchangeable
testfun(plotarg=list(type="l"), legarg=list(col="blue", pch=16) )