R help - Feb 2009 - 1.095e+09 for integers

I've had a very long file written out by R with write.table, with  
fields of time values, converted from POSIXlt as.numeric.  Among 2.5  
million values, very few had 6 trailing zeroes, and those were output  
in scientific notation as in the subject.  Is this the default  
behavior for long integers, and how can it be turned off (with all  
digits for any integer field in write.table)?  This is important to  
interoperate with other languages through such text dumps, as some do  
not expect scientific notation for integers, only for floats.

Cheers,
Alexy

I don't think you had 'integers' but integer-valued doubles: try 
as.integer to get an integer variable. E.g.

x <- 1.1*(10^(1:8))
> write.table(data.frame(x, as.integer(x)), "")
"x" "as.integer.x."
"1" 11 11
"2" 110 110
"3" 1100 1100
"4" 11000 11000
"5" 110000 110000
"6" 1100000 1100000
"7" 1.1e+07 11000000
"8" 1.1e+08 110000000

Or see options(scipen=)
> options(scipen = 9)
> write.table(data.frame(x, as.integer(x)), "")
"x" "as.integer.x."
"1" 11 11
"2" 110 110
"3" 1100 1100
"4" 11000 11000
"5" 110000 110000
"6" 1100000 1100000
"7" 11000000 11000000
"8" 110000000 110000000

On Sun, 22 Feb 2009, Alexy Khrabrov wrote:
> I've had a very long file written out by R with write.table, with
fields of
> time values, converted from POSIXlt as.numeric.  Among 2.5 million values, 
> very few had 6 trailing zeroes, and those were output in scientific
notation
> as in the subject.  Is this the default behavior for long integers, and how
> can it be turned off (with all digits for any integer field in
write.table)?
They are already for integers: see above.
> This is important to interoperate with other languages through such text 
> dumps, as some do not expect scientific notation for integers, only for 
> floats.
But you almost certainly had 'floats' in R.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

On Sun, 2009-02-22 at 23:42 -0500, Alexy Khrabrov wrote:
> I've had a very long file written out by R with write.table, with  
> fields of time values, converted from POSIXlt as.numeric.  Among 2.5  
> million values, very few had 6 trailing zeroes, and those were output  
> in scientific notation as in the subject.  Is this the default  
> behavior for long integers, and how can it be turned off (with all  
> digits for any integer field in write.table)?  This is important to  
> interoperate with other languages through such text dumps, as some do  
> not expect scientific notation for integers, only for floats.
> 
> Cheers,
> Alexy
Alexy 

If I understood your problem you have something like this


as.numeric(12345678912345678)
[1] 1.234568e+16

In this case your solution is using format, like this

format(as.numeric(12345678912345678),scientific=FALSE)
[1] "12345678912345678


-- 
Bernardo Rangel Tura, M.D,MPH,Ph.D
National Institute of Cardiology
Brazil