R help - Jul 2006 - problem of fixed-formated output using sprintf

Dear R users:

I'm trying to generate a output file with fixed format using function
"sprintf" in R. However, the execution time in R is very long even the
toy data (smaller size df) seems to work fine. The syntax that I used is as
follows:

df.fmt <- sprintf("%2s%2s%2.4f", df$v1, df$v2, df$v3)
write.table(df.fmt, output.name,...)  

The actual dataset is a df with the dimention of 67944 by 34. I'm wondering
whether there is an elegant way of doing it. I would like output in a txt file.

Many thanks.


Yihsu Chen
The Johns Hopkins University

Are you sure it is the sprintf vs. write.table?  I constructed a dataframe
of your size and it took less than 1 second to do the sprintf:
> system.time(df.fmt <- sprintf("%2s%2s%4.2f", df$V1, df$V2,
df$V3))
[1] 0.70 0.00 0.73   NA   NA
> str(df)
`data.frame':   67944 obs. of  34 variables:
 $ V1 : chr  "0.2655" "0.3721" "0.5729"
"0.9082" ...
 $ V2 : chr  "0.2655" "0.3721" "0.5729"
"0.9082" ...
 $ V3 : num  0.0642 0.5316 0.5466 0.2798 0.4931 ...
 $ V4 : num  0.8430 0.8279 0.1552 0.5153 0.0725 ...
 $ V5 : num  0.922 0.780 0.811 0.847 0.223 ...


If you want to write this string out to a file, then use 'cat'.  If you
add
'\n' to the sprintf, you will get something like this:
> cat(df.fmt[1:5])
0.26550.26550.06
 0.37210.37210.53
 0.57290.57290.55
 0.90820.90820.28
 0.20170.20170.49
>

On 7/11/06, YIHSU CHEN <yschen@jhu.edu> wrote:
>
> Dear R users:
>
> I'm trying to generate a output file with fixed format using function
> "sprintf" in R. However, the execution time in R is very long
even the toy
> data (smaller size df) seems to work fine. The syntax that I used is as
> follows:
>
> df.fmt <- sprintf("%2s%2s%2.4f", df$v1, df$v2, df$v3)
> write.table(df.fmt, output.name,...)
>
> The actual dataset is a df with the dimention of 67944 by 34. I'm
> wondering whether there is an elegant way of doing it. I would like output
> in a txt file.
>
> Many thanks.
>
>
> Yihsu Chen
> The Johns Hopkins University
>
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>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390 (Cell)
+1 513 247 0281 (Home)

What is the problem you are trying to solve?

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