R help - Jul 2011 - binary conversion list to data.frame with plyr... AND NO LOOPS!

Happy weekend helpeRs!

As usual, I'm stumped by R...

My plan was to take an integer number, convert it to binary and wind
up with a data.frame where each column is either 1 or 0 so I can see
which bits are changing:

bb<-function(i) ifelse(i, paste(bb(i %/% 2), i %% 2, sep=""),
"")
my.dat<-c(36,40,10,4)
my.binary.dat<-bb(my.dat)
my.list<-strsplit(my.binary.dat,'')

max.len<-max(ldply(my.list,length))
len<-length(my.list)
my.df<-data.frame(two=rep(0,len),four=rep(0,len),eight=rep(0,len),sixteen=rep(0,len),thirtytwo=rep(0,len),sixtyfour=rep(0,len))
for(i in 1:length(my.list)){
	for(j in 1:length(my.list[[i]])){
		my.df[i,max.len-length(my.list[[i]])+j]<-my.list[[i]][j]	
	}
}

But this isn't exactly feasable on a million+ rows where some binary
numbers are 20 digits...  I know theres a way without loops I just
know it!

Ideally, I can do this to multiple columns of a data.frame and have
them named accordingly (V1.two,V1.four... V2.two,V2.four, etc.)


Thanks,

Justin

try this:
> x <- c(36, 40, 10, 4)
> x.m <- matrix(as.integer(intToBits(x)), byrow = TRUE, ncol = 32)[, 1:20]
> x.m <- data.frame(x.m)  # convert to data.frame
> x.m
  X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15 X16 X17 X18 X19 X20
1  0  0  1  0  0  1  0  0  0   0   0   0   0   0   0   0   0   0   0   0
2  0  0  0  1  0  1  0  0  0   0   0   0   0   0   0   0   0   0   0   0
3  0  1  0  1  0  0  0  0  0   0   0   0   0   0   0   0   0   0   0   0
4  0  0  1  0  0  0  0  0  0   0   0   0   0   0   0   0   0   0   0  
0
>

On Fri, Jul 8, 2011 at 6:39 PM, Justin Haynes <jtor14 at gmail.com>
wrote:
> Happy weekend helpeRs!
>
> As usual, I'm stumped by R...
>
> My plan was to take an integer number, convert it to binary and wind
> up with a data.frame where each column is either 1 or 0 so I can see
> which bits are changing:
>
> bb<-function(i) ifelse(i, paste(bb(i %/% 2), i %% 2, sep=""),
"")
> my.dat<-c(36,40,10,4)
> my.binary.dat<-bb(my.dat)
> my.list<-strsplit(my.binary.dat,'')
>
> max.len<-max(ldply(my.list,length))
> len<-length(my.list)
>
my.df<-data.frame(two=rep(0,len),four=rep(0,len),eight=rep(0,len),sixteen=rep(0,len),thirtytwo=rep(0,len),sixtyfour=rep(0,len))
> for(i in 1:length(my.list)){
> ? ? ? ?for(j in 1:length(my.list[[i]])){
> ? ? ? ? ? ? ? ?my.df[i,max.len-length(my.list[[i]])+j]<-my.list[[i]][j]
> ? ? ? ?}
> }
>
> But this isn't exactly feasable on a million+ rows where some binary
> numbers are 20 digits... ?I know theres a way without loops I just
> know it!
>
> Ideally, I can do this to multiple columns of a data.frame and have
> them named accordingly (V1.two,V1.four... V2.two,V2.four, etc.)
>
>
> Thanks,
>
> Justin
>
> ______________________________________________
> R-help at 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.
>


-- 
Jim Holtman
Data Munger Guru

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