[R] data type for block data?

[Stephen Tucker]

Hi Paul,

Hope this is what you're looking for:

## reading in text (the first 13 rows of cc from your posting)
## and using smaller indices [(3,8) instead of (10,40)]
## for this example
> cc <- "mode<-"(do.call(rbind,
+        strsplit(readLines(textConnection(txt))[-1],"[ ]{2,}"))[,-1],
+        "numeric")
> index <- c(3,8)

## (1) convert cc to data frame
## (2) split according to factors produced by cut()
## (3) apply data.matrix() to each element of list
##     produced by split() to convert back to numeric matrix
> s <- lapply(split(as.data.frame(cc),
+                   f=cut(1:nrow(cc),breaks=c(-Inf,index,Inf))),
+             data.matrix)

## return result. now s[[1]] contains the first "block",
## s[[2]] contains the second "block", and so on.
> s
$`(-Inf,3]`
  V1 V2
1  1 26
2  2 27
3  3 28

$`(3,8]`
  V1 V2
4  4 29
5  5 30
6  6 31
7  7 32
8  8 33

$`(8, Inf]`
   V1 V2
9   9 34
10  1 27
11  1 28
12  2 30
13  3 34


--- "H. Paul Benton" <hpbenton at scripps.edu> wrote:

> Dear All,
> 
> 
>     I have a matrix with data that is not organised. I would like to go
> through this and extract it. Each feature has 2 vectors which express
> the data. I also have an index of the places where the data should be cut.
> eg.
> >class(cc)
> "matrix"
> >cc
>       [,1] [,2]
>  [1,]    1   26
>  [2,]    2   27
>  [3,]    3   28
>  [4,]    4   29
>  [5,]    5   30
>  [6,]    6   31
>  [7,]    7   32
>  [8,]    8   33
>  [9,]    9   34
> [10,]    1   27
> [11,]    1   28
> [12,]    2   30
> [13,]    3   34
> ect......
> > index
> [1] "10" "40"
> 
> 
> Is there a way to take cc[i:index[i-1],] to another format as to where
> each block could be worked on separately. ie so in one block would be
> rows1:10 the next block would be rows11:40 and so on.
> 
> Thanks,
> 
> Paul
> 
> 
> 
> -- 
> Research Technician
> Mass Spectrometry
>    o The
>   /
> o Scripps
>   \
>    o Research
>   /
> o Institute
> 
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