get the name of the output variable in R -

get the name of the output variable in R -

sorry poor english

is there way in r name used returning values of function within function, same way can grab name of input variables "substitute"??. mean "outputname" function:

myfun=function(x){ namein=substitute(x) nameout=outputname() out=x*2 cat("the name of input ", namein," , value:\n") print(x) cat("the name of output ", nameout, "and value:\n") print(out) return(out) }

this wish:

> myinput=12; > myoutput=myfun(myinput) name of input myinput , value: [1] 12 name of output myoutput , value: [1] 24 > myoutput [1] 24

i've been looking reply , going crazy. seems simple can't find anything.

thanks

here 2 workarounds comments. first uses environments pass reference. output variable supplied argument myfun1. sec uses assign assign homecoming value of myfun2 output variable , retrieves name of ouput variable examining phone call stack.

myinput <- 12

workaround 1

myfun1 <- function(x, output){ namein=substitute(x) nameout=substitute(output) output$value=x*2 cat("the name of input ", namein," , value:\n") print(x) cat("the name of output ", nameout, "and value:\n") print(output$value) } myoutput <- new.env() myoutput$value <- 1 myfun1(myinput, myoutput) # name of input myinput , value: # [1] 12 # name of output myoutput , value: # [1] 24 myoutput$value # [1] 24

workaround 2

suggested @roland (my interpretation of comment, @ least):

myfun2=function(x){ namein=substitute(x) nameout=as.list(sys.calls()[[1]])[[2]] out=x*2 cat("the name of input ", namein," , value:\n") print(x) cat("the name of output ", nameout, "and value:\n") print(out) return(out) } assign('myoutput', myfun2(myinput)) # name of input myinput , value: # [1] 12 # name of output myoutput , value: # [1] 24 myoutput # [1] 24

r