11 messages · Henrik Bengtsson, Dylan Beaudette, (Ted Harding) +4 more
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
Please give reproducible example, more information on your troubleshooting and sessionInfo(). Cannot reproduce:
pathname <- "empty.txt" cat(file=pathname) print(file.info(pathname))
size isdir mode mtime ctime
empty.txt 0 FALSE 666 2010-01-01 12:50:55 2010-01-01 12:45:34
atime exe
empty.txt 2010-01-01 12:45:34 no
read.table(pathname)
Error in read.table(pathname) : no lines available in input
sessionInfo()
R version 2.10.1 Patched (2009-12-24 r50837) i386-pc-mingw32 locale: [1] LC_COLLATE=English_United States.1252 [2] LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 [4] LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base /Henrik
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
?try
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
If I understand the point of your query correctly, the following, from "?read.table", would be relevant: Value: A data frame (?data.frame?) containing a representation of the data in the file. Empty input is an error unless "col.names" is specified, when a 0-row data frame is returned: similarly giving just a header line if "header = TRUE" results in a 0-row data frame. Note that in either case the columns will logical unless ?colClasses? was supplied. The result would not be NULL, but can be tested for zero rows. Hoping this helps, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk> Fax-to-email: +44 (0)870 094 0861 Date: 01-Jan-10 Time: 20:55:35 ------------------------------ XFMail ------------------------------
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Please reread my original post. You run it in a shell. I run it in a script.
Please give reproducible example, more information on your troubleshooting and sessionInfo(). ?Cannot reproduce:
pathname <- "empty.txt" cat(file=pathname) print(file.info(pathname))
? ? ? ? ?size isdir mode ? ? ? ? ? ? ? mtime ? ? ? ? ? ? ? ctime empty.txt ? ?0 FALSE ?666 2010-01-01 12:50:55 2010-01-01 12:45:34 ? ? ? ? ? ? ? ? ? ? ? ?atime exe empty.txt 2010-01-01 12:45:34 ?no
read.table(pathname)
Error in read.table(pathname) : no lines available in input
sessionInfo()
R version 2.10.1 Patched (2009-12-24 r50837) i386-pc-mingw32 locale: [1] LC_COLLATE=English_United States.1252 [2] LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 [4] LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats ? ? graphics ?grDevices utils ? ? datasets ?methods ? base /Henrik On Fri, Jan 1, 2010 at 12:41 PM, Peng Yu <pengyu.ut at gmail.com> wrote:
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
On Fri, Jan 1, 2010 at 2:54 PM, Dylan Beaudette
?try
This works. Thank you!
f=try(read.table("empty_data.txt"))
Error in read.table("empty_data.txt") : no lines available in input
if(class(f)=='try-error') {
+ f=NULL + }
print(f)
NULL
g=try(read.table("data.txt"))
print(g)
V1 V2 V3 V4 1 name title1 title2 title3 2 row1 10.1 20.1 30.1 3 row2 12.1 22.1 32.1
On Fri, Jan 1, 2010 at 12:41 PM, Peng Yu <pengyu.ut at gmail.com> wrote:
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
?try
df <- try(read.table(...))
if (inherits(df, 'try-error')){? what to do if file empty }
For the case of using try, it is better to use inherits() rather than class(), or it doesn't matter?
On Fri, Jan 1, 2010 at 3:55 PM, Ted Harding <Ted.Harding at manchester.ac.uk> wrote:
On 01-Jan-10 20:41:52, Peng Yu wrote:
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
If I understand the point of your query correctly, the following, from "?read.table", would be relevant: Value: ?A data frame (?data.frame?) containing a representation of the ?data in the file. ?Empty input is an error unless "col.names" is specified, when a ?0-row data frame is returned: similarly giving just a header line ?if "header = TRUE" results in a 0-row data frame. ?Note that in ?either case the columns will logical unless ?colClasses? was ?supplied. The result would not be NULL, but can be tested for zero rows. Hoping this helps, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk> Fax-to-email: +44 (0)870 094 0861 Date: 01-Jan-10 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Time: 20:55:35 ------------------------------ XFMail ------------------------------
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?
On Fri, Jan 1, 2010 at 2:54 PM, Dylan Beaudette <dylan.beaudette at gmail.com> wrote:
?try
This works. Thank you!
f=try(read.table("empty_data.txt"))
Error in read.table("empty_data.txt") : no lines available in input
One more question. Is there a way to suppress the output to the screen
'Error in read.table("empty_data.txt") : no lines available in input'?
if(class(f)=='try-error') {
+ ? f=NULL + }
print(f)
NULL
g=try(read.table("data.txt"))
print(g)
? ?V1 ? ? V2 ? ? V3 ? ? V4 1 name title1 title2 title3 2 row1 ? 10.1 ? 20.1 ? 30.1 3 row2 ? 12.1 ? 22.1 ? 32.1
On Fri, Jan 1, 2010 at 12:41 PM, Peng Yu <pengyu.ut at gmail.com> wrote:
read.table terminates the program if the input file is empty. Is there way to let the program continue and return me a NULL instead of terminating the program? $ Rscript read_empty.R
read.table("empty_data.txt")
Error in read.table("empty_data.txt") : no lines available in input
Execution halted
$ cat read_empty.R
read.table("empty_data.txt")
$ cat empty_data.txt; echo EOF
EOF
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
On Fri, Jan 1, 2010 at 3:19 PM, Peng Yu <pengyu.ut at gmail.com> wrote:
On Fri, Jan 1, 2010 at 2:54 PM, Dylan Beaudette <dylan.beaudette at gmail.com> wrote:
?try
This works. Thank you!
f=try(read.table("empty_data.txt"))
Error in read.table("empty_data.txt") : no lines available in input
One more question. Is there a way to suppress the output to the screen
'Error in read.table("empty_data.txt") : no lines available in input'?
As always, you should try reading the full help page. I know it must seem onerous but in this case (re-?)read all of the help page for "try".
David.
>
>>> if(class(f)=='try-error') {
>> + f=NULL
>> + }
>>> print(f)
>> NULL
>>> g=try(read.table("data.txt"))
>>> print(g)
>> V1 V2 V3 V4
>> 1 name title1 title2 title3
>> 2 row1 10.1 20.1 30.1
>> 3 row2 12.1 22.1 32.1
>>>
>>
>>
>>> On Fri, Jan 1, 2010 at 12:41 PM, Peng Yu <pengyu.ut at gmail.com>
>>> wrote:
>>>> read.table terminates the program if the input file is empty. Is
>>>> there
>>>> way to let the program continue and return me a NULL instead of
>>>> terminating the program?
>>>>
>>>> $ Rscript read_empty.R
>>>>> read.table("empty_data.txt")
>>>> Error in read.table("empty_data.txt") : no lines available in input
>>>> Execution halted
>>>> $ cat read_empty.R
>>>> read.table("empty_data.txt")
>>>> $ cat empty_data.txt; echo EOF
>>>> EOF
>
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
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