Le mer. 21 mai à 04:38, Petr PIKAL a écrit :
Hallo
[EMAIL PROTECTED] napsal dne 21.05.2008 09:42:40:
Hi,
I just started using R for about one week and I have few problems.
i)I have a problem in finding right function to convert a table of
natural
numbers to bitwise. For a simple example;
I have the below table:-
Column Col1 Col2 Col3
Sample1 5 7 10
Sample2 0 2 1
Sample3 4 0 0
Supposedly i wanted to convert to :-
Column Col1 Col2 Col3
Sample1 1 1 1
Sample2 0 1 1
Sample3 1 0 0
data<-read.table("clipboard", header=T
If data is your data frame,
data.bit<-data.frame(column=data[,1],(data[,-1]>0)*1)
sign(data) will also do.
Vincent
ii)Besides, I would like to create a formula of Sum(3*(Element in
each
column for a row))..does it equivalent to 3*(data[1:3,1:2]) in this
case?or
I need to have Sum(3*(data[1:3,1:2])). Basically I wanted to mutliply
each
element of column table of a row and sum it up.
Rather complicated.
3*(data[1:3,2:3])
Col1 Col2
1 15 21
2 0 6
3 12 0
sum(3*(data[1:3,2:3]))
[1] 54
Works but I am suspicious that you wont something else.
iii)I would also like to know how to insert an if else statement
where
in
the above case, I wanted to check if data[1:3,]
returns me 1 or 0, it will execute some calculations.
I refer to the R intro pdf and it mentioned using if (expr_1 ) expr_2
else
expr_3. Does that mean if(data[1:3,1:2])>0 output[1:3,1:2]=0
else output[1:3,1:2]="100". If I did this command, how does R knows
which
row and column to map the output with?
If ... else ... is usually for working as programming steps
ifelse(..., ..., ...)
works with objects and is parts. You shall think first how to do your
calculations with whole objects, it is usually more effective.
Regards
Petr
Please advise. Appreciate alot. Thanks.
[[alternative HTML version deleted]]
______________________________________________
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.
______________________________________________
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.
______________________________________________
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.
