R help - Aug 2007 - sink behavior

There is a package called 'safe' that produces an object which I can 
only write to a file using the sink() function.  It works fine if the 
sink() command is not inside of a function, but it does not write 
anything to the file if the command is within a function.

Sample code:
# Using a matrix because as a simple example.
dumpMatrix = function(mat) {
    sink(file = "mat.txt")
    mat
    sink(NULL)
}

# This will write the file correctly.
x = matrix(100, 10, 10)
sink(file = "x.txt")
x
sink(NULL)

# This will create an empty file.
dumpMatrix(x)

R 2.5.1
Windows XP, SP2

The sink() docs are full of warnings, but I'm not clear which one I've 
violated with this example.

Dan

'sink' will capture 'printed' output from your program.  Try:
> # Using a matrix because as a simple example.
> dumpMatrix = function(mat) {
>    sink(file = "mat.txt")
>    print(mat)
>    sink(NULL)
> }
In this case, there is an explicit 'print' statement.  At the command
line, there is an implicit 'print' when you give an object name.


On 8/6/07, Daniel Gatti <dmgatti at email.unc.edu>
wrote:
> There is a package called 'safe' that produces an object which I
can
> only write to a file using the sink() function.  It works fine if the
> sink() command is not inside of a function, but it does not write
> anything to the file if the command is within a function.
>
> Sample code:
> # Using a matrix because as a simple example.
> dumpMatrix = function(mat) {
>    sink(file = "mat.txt")
>    mat
>    sink(NULL)
> }
>
> # This will write the file correctly.
> x = matrix(100, 10, 10)
> sink(file = "x.txt")
> x
> sink(NULL)
>
> # This will create an empty file.
> dumpMatrix(x)
>
> R 2.5.1
> Windows XP, SP2
>
> The sink() docs are full of warnings, but I'm not clear which one
I've
> violated with this example.
>
> Dan
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
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> 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 you are trying to solve?