R help - Jan 2008 - Filling data frame data into a matrix - please help

Dear group, 
I have a data.frame (d1) with various elements and a
matrix (m1) created with NA (or 1s). I want to read
each row,column in d1 and fill its numeric value in
m1.

Could some one help me because I have 130K rows and
500 column data.frame object and I was told that a for
loop will take a long time. 

Thank you.
> r1 <- c("A","A","B","B")
> c1 <-
c("Apple","Andy","Boy","Ball")
> v1 <- as.numeric(c(0.001,0.02,0.3,NA))
> d1 <- cbind(r1,c1,as.numeric(v1))
> d1 <- data.frame(d1)
> d1
  r1    c1    V3
1  A Apple 0.001
2  A  Andy  0.02
3  B   Boy   0.3
4  B  Ball  <NA>

> m1 <- matrix(NA,2,4)
> rownames(m1)<- unique(r1)
> colnames(m1)<-unique(c1)
> m1
  Apple Andy Boy Ball
A    NA   NA  NA   NA
B    NA   NA  NA   NA


I want to have:

result:


  Apple   Andy  Boy  Ball
A 0.001   0.02  NA    NA
B  NA     NA    0.3   NA


thanks
Srini


     
____________________________________________________________________________________
Be a better friend, newshound, and

Try this:

d1 <- data.frame(d1)
d1$V3 <- as.numeric(as.character(d1$V3))
xtabs(V3 ~ r1+c1, data=d1)

You can substitute 0 with NA:

d1.tb <- xtabs(V3 ~ r1+c1, data=d1)
d1.tb[d1.tb==0] <- NA


On 24/01/2008, Srinivas Iyyer <srini_iyyer_bio at yahoo.com>
wrote:
> Dear group,
> I have a data.frame (d1) with various elements and a
> matrix (m1) created with NA (or 1s). I want to read
> each row,column in d1 and fill its numeric value in
> m1.
>
> Could some one help me because I have 130K rows and
> 500 column data.frame object and I was told that a for
> loop will take a long time.
>
> Thank you.
>
> > r1 <- c("A","A","B","B")
> > c1 <-
c("Apple","Andy","Boy","Ball")
> > v1 <- as.numeric(c(0.001,0.02,0.3,NA))
> > d1 <- cbind(r1,c1,as.numeric(v1))
> > d1 <- data.frame(d1)
> > d1
>   r1    c1    V3
> 1  A Apple 0.001
> 2  A  Andy  0.02
> 3  B   Boy   0.3
> 4  B  Ball  <NA>
>
>
> > m1 <- matrix(NA,2,4)
> > rownames(m1)<- unique(r1)
> > colnames(m1)<-unique(c1)
> > m1
>   Apple Andy Boy Ball
> A    NA   NA  NA   NA
> B    NA   NA  NA   NA
>
>
> I want to have:
>
> result:
>
>
>   Apple   Andy  Boy  Ball
> A 0.001   0.02  NA    NA
> B  NA     NA    0.3   NA
>
>
> thanks
> Srini
>
>
>      
____________________________________________________________________________________
> Be a better friend, newshound, and
>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

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Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O