[R] about eval and eval.parent
ronggui
042045003 at fudan.edu.cn
Fri Nov 18 15:57:30 CET 2005
x<-1
f<-function(){
x<-3
eval(substitute(x+y,list(y=10)))
}
f() #13
x<-1
f<-function(){
x<-3
eval(substitute(x+y,list(y=10)), envir = sys.frame(sys.parent()))
}
f() #11
x<-1
f<-function(){
x<-3
eval.parent(substitute(x+y,list(y=10)))
}
f()#11
the help page says:
"If 'envir' is
not specified, then 'sys.frame(sys.parent())', the environment
where the call to 'eval' was made is used. "
But it seems that the first one is not equal to the second one.
Thank you!
2005-11-18
------
Deparment of Sociology
Fudan University
My new mail addres is ronggui.huang at gmail.com
Blog:http://sociology.yculblog.com
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