Hi,
You can leverage read.table using a textConnection:
> txt <- "x,y,z,a,b,c,d<d>a,b,c,d,e,f,g<d>"
> con <- textConnection( gsub( "<d>", "\\\n", txt ) )
> read.table( con, sep = "," )
V1 V2 V3 V4 V5 V6 V7
1 x y z a b c d
2 a b c d e f g
> close( con )
Romain
Le 10/09/10 06:41, rajesh j a écrit :
Ok. These operations are on a string and the result is added to a
data.frame.
I have strings of the form
"x,y,z,a,b,c,d<d>a,b,c,d,e,f,g<d>
essentially comma separated values delimited by a<d>
I first do a
unlist(strsplit(string,split="<d>"))
and then a
strsplit(string,split=",")
The list of vectors i end up with is added row by row to a preallocated
data.frame like..
df[i,]<-list[[i]]
all of this is in a for loop and it runs for 1000 times atleast and the
strings are 7000 to 8000 characters in length
On Fri, Sep 10, 2010 at 9:14 AM, jim holtman<jholt...@gmail.com> wrote:
First thing to do is to use Rprof to profile your code to see where
the time is being spent, then you can make a decision as to what to
change. Are you carrying out the operations on a dataframe, if so can
you change it to a matrix for some of the operations? You have
provided no idea of what your code or data looks like, or how often
each of the operations is being done.
There are probably many ways of speeding up the code, but with no idea
of what the code is, no solutions can be specified.
On Thu, Sep 9, 2010 at 11:09 PM, rajesh j<akshay.raj...@gmail.com> wrote:
Hi,
I perform the operations unlist,strsplit,gsub and the for loop on a lot
of
strings and its heavily slowing down the overall system. Is there some
way
for me to speeden up these operations..maybe like alternate versions that
exist which use multiprocessors etc.
--
Rajesh.J
--
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
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