I'm having trouble with something that looks easy. (And I'm sure it
will be easier within about 1 minute of receiving my first response.)
Thanks in advance.
I have a collection of data frames that I need to add columns, do some
calculations and then fill in the new columns. Since I have a large
number of similar data frames I want to do this with functions to make
the code more readable and ensure that every frame is done the same
way. However my simple example doesn't work as I expected it to:
Here the R example code to cut and paste. The basic idea is to copy
positive values of y into p and negative values into l.
<START COPY>
AddCols = function (MyFrame) {
MyFrame$p<-0
MyFrame$l<-0
return(MyFrame)
}
BinPosNeg = function (MyFrame) {
ifelse(MyFrame$y>0, MyFrame$p<-MyFrame$y, MyFrame$l<MyFrame$y)
return(MyFrame)
}
F1 <- data.frame(x=1:10, y=-4:5)
F1
F1 <- AddCols(F1)
F1
F1 <- BinPosNeg(F1)
F1
<END COPY>
My results below are weird. After the last function call F1 acts like
BinPosNeg always evaluated MyFrame$y>0. All updates went into p - none
into l.
What am I doing wrong?
Thanks,
Mark
MY RESULTS:
> AddCols = function (MyFrame) {
+ MyFrame$p<-0
+ MyFrame$l<-0
+ return(MyFrame)
+ }
>
> BinPosNeg = function (MyFrame) {
+ ifelse(MyFrame$y>0, MyFrame$p<-MyFrame$y, MyFrame$l<MyFrame$y)
+ return(MyFrame)
+ }
>
> F1 <- data.frame(x=1:10, y=-4:5)
> F1
x y
1 1 -4
2 2 -3
3 3 -2
4 4 -1
5 5 0
6 6 1
7 7 2
8 8 3
9 9 4
10 10 5
> F1 <- AddCols(F1)
> F1
x y p l
1 1 -4 0 0
2 2 -3 0 0
3 3 -2 0 0
4 4 -1 0 0
5 5 0 0 0
6 6 1 0 0
7 7 2 0 0
8 8 3 0 0
9 9 4 0 0
10 10 5 0 0
> F1 <- BinPosNeg(F1)
> F1
x y p l
1 1 -4 -4 0
2 2 -3 -3 0
3 3 -2 -2 0
4 4 -1 -1 0
5 5 0 0 0
6 6 1 1 0
7 7 2 2 0
8 8 3 3 0
9 9 4 4 0
10 10 5 5 0
>
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
