Re: [R-pkg-devel] Working with connections - What is correct?
Hi Dirk,
Thanks for your response, I get the point on return(). For me, it is a security
blanket - I just need to let that go rather than justify keeping it. I will
refactor the connections and just get comfortable without return().
Thanks,
Glenn
On Aug 10, 2015, at 09:59 PM, Dirk Eddelbuettel e...@debian.org wrote:
On 11 August 2015 at 02:09, Glenn Schultz wrote:
| All,
| Is my function just plain wrong or is it just programming style? I use
connections because SODA (software for data analysis) recommends using
connections when working with serialized files.
Nothing wrong with connections. Many of us use them.
| First, after researching the use of return() - following Joshua's comment and
others I found a post on SO regarding return().
http://stackoverflow.com/questions/11738823/explicitly-calling-return-in-a-function-or-not
Let's try once more. The function foo()
foo - function() {
x - 2
return(x)
x - 3
}
will return what value? Ie what does 'print(foo())' show?
| Second, Hadley's point regarding the use of RDS in gz function being a little
strange. Following the help files the function is fashioned after the following
which I found in R help files:
IIRC what Hadley was trying to say what you do _not_ need to compress before
inserting into a rds file as the rds file format compresses by default.
In other words compression comes for free, and effortlessly so.
Hth, Dirk
| ## Less convenient ways to restore the object
| ## which demonstrate compatibility with unserialize()
| con - gzfile(women.rds, rb)
| identical(unserialize(con), women)
| close(con)
| con - gzfile(women.rds, rb)
| wm - readBin(con, raw, n = 1e4) # size is a guess
| close(con)
| identical(unserialize(wm), women)
|
| With respect to the first, I understand why my function would be considered buggy - that can be fixed. It is the case, generally speaking, one does not need return() when programming in R; it is a functional language. However, some use return() and one finds return(value) in the R help files. Is it a strict no-no to use return()?
|
| With respect to the second, The function can be refactored and reduced to readRDS(). My question, is using gz file overkill or just plain wrong?
| What is considered best practice?
|
| -Glenn
|
|
| On Aug 09, 2015, at 09:04 AM, Joshua Ulrich josh.m.ulr...@gmail.com wrote:
|
| On Sun, Aug 9, 2015 at 8:59 AM, Glenn Schultz glennmschu...@me.com wrote:
| Hi All,
|
| I use connections to open and close data folders needed by my package.
| After each function closes I get the following warnings (depending on the
| connection that has been opened).
|
| 10: closing unused connection 3
|
(/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds)
|
| Below is the connection function that is related to the above warning:
|
| #
| #' A connection function to BondData calling MBS cusps
| #'
| #' Opens a connection to the BondData folder to call MBS cusip data
| #' @param MBS.id A character string the MBS.id or cusip number current
| MBS.id is supported
| #' @export
| MBS - function(MBS.id = character){
| MBS.Conn - gzfile(description = paste(system.file(package
| = BondLab),
| /BondData/, MBS.id, .rds, sep = ), open
| = rb)
| MBS - readRDS(MBS.Conn)
| return(MBS)
| close.connection(MBS.Conn)
| }
|
| I have googled this warning and it seems to be triggered when a function
| terminates and the connection is open. But, I think the connection function
| closes the connection once the object is returned. What am I doing wrong?
|
| Your call to return() exits the function, so the close.connection()
| call is never evaluated. Considering using on.exit() to close the
| connection, since it will close the connection regardless of how the
| function exits (e.g. because of an error).
|
| -Glenn
| __
| R-package-devel@r-project.org mailing list
| https://stat.ethz.ch/mailman/listinfo/r-package-devel
|
|
|
| --
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| FOSS Trading | http://www.fosstrading.com
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Re: [R-pkg-devel] Working with connections - What is correct?
All,
Is my function just plain wrong or is it just programming style? I use
connections because SODA (software for data analysis) recommends using
connections when working with serialized files.
First, after researching the use of return() - following Joshua's comment and
others I found a post on SO regarding return().
http://stackoverflow.com/questions/11738823/explicitly-calling-return-in-a-function-or-not
Second, Hadley's point regarding the use of RDS in gz function being a little
strange. Following the help files the function is fashioned after the following
which I found in R help files:
## Less convenient ways to restore the object
## which demonstrate compatibility with unserialize()
con - gzfile(women.rds, rb)
identical(unserialize(con), women)
close(con)
con - gzfile(women.rds, rb)
wm - readBin(con, raw, n = 1e4) # size is a guess
close(con)
identical(unserialize(wm), women)
With respect to the first, I understand why my function would be considered
buggy - that can be fixed. It is the case, generally speaking, one does not
need return() when programming in R; it is a functional language. However, some use
return() and one finds return(value) in the R help files. Is it a strict no-no to use
return()?
With respect to the second, The function can be refactored and reduced to
readRDS(). My question, is using gz file overkill or just plain wrong?
What is considered best practice?
-Glenn
On Aug 09, 2015, at 09:04 AM, Joshua Ulrich josh.m.ulr...@gmail.com wrote:
On Sun, Aug 9, 2015 at 8:59 AM, Glenn Schultz glennmschu...@me.com wrote:
Hi All,
I use connections to open and close data folders needed by my package.
After each function closes I get the following warnings (depending on the
connection that has been opened).
10: closing unused connection 3
(/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds)
Below is the connection function that is related to the above warning:
#
#' A connection function to BondData calling MBS cusps
#'
#' Opens a connection to the BondData folder to call MBS cusip data
#' @param MBS.id A character string the MBS.id or cusip number current
MBS.id is supported
#' @export
MBS - function(MBS.id = character){
MBS.Conn - gzfile(description = paste(system.file(package
= BondLab),
/BondData/, MBS.id, .rds, sep = ), open
= rb)
MBS - readRDS(MBS.Conn)
return(MBS)
close.connection(MBS.Conn)
}
I have googled this warning and it seems to be triggered when a function
terminates and the connection is open. But, I think the connection function
closes the connection once the object is returned. What am I doing wrong?
Your call to return() exits the function, so the close.connection()
call is never evaluated. Considering using on.exit() to close the
connection, since it will close the connection regardless of how the
function exits (e.g. because of an error).
-Glenn
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Re: [R-pkg-devel] Working with connections
Also it's a little strange to put an RDS file _inside_ a gz, since
normally the compression is done internally.
And are you sure you should be exposing this data via a function,
rather than using the regular package data mechanism?
Hadley
On Sun, Aug 9, 2015 at 7:04 AM, Joshua Ulrich josh.m.ulr...@gmail.com wrote:
On Sun, Aug 9, 2015 at 8:59 AM, Glenn Schultz glennmschu...@me.com wrote:
Hi All,
I use connections to open and close data folders needed by my package.
After each function closes I get the following warnings (depending on the
connection that has been opened).
10: closing unused connection 3
(/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds)
Below is the connection function that is related to the above warning:
#
#' A connection function to BondData calling MBS cusps
#'
#' Opens a connection to the BondData folder to call MBS cusip data
#' @param MBS.id A character string the MBS.id or cusip number current
MBS.id is supported
#' @export
MBS - function(MBS.id = character){
MBS.Conn - gzfile(description = paste(system.file(package
= BondLab),
/BondData/, MBS.id, .rds, sep = ), open
= rb)
MBS - readRDS(MBS.Conn)
return(MBS)
close.connection(MBS.Conn)
}
I have googled this warning and it seems to be triggered when a function
terminates and the connection is open. But, I think the connection function
closes the connection once the object is returned. What am I doing wrong?
Your call to return() exits the function, so the close.connection()
call is never evaluated. Considering using on.exit() to close the
connection, since it will close the connection regardless of how the
function exits (e.g. because of an error).
-Glenn
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Re: [R-pkg-devel] Working with connections
Hi Joshua, Thank-you.
I did not realize that the call to return closed the connection
-Glenn
On Aug 9, 2015, at 9:04 AM, Joshua Ulrich josh.m.ulr...@gmail.com wrote:
On Sun, Aug 9, 2015 at 8:59 AM, Glenn Schultz glennmschu...@me.com wrote:
Hi All,
I use connections to open and close data folders needed by my package.
After each function closes I get the following warnings (depending on the
connection that has been opened).
10: closing unused connection 3
(/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds)
Below is the connection function that is related to the above warning:
#
#' A connection function to BondData calling MBS cusps
#'
#' Opens a connection to the BondData folder to call MBS cusip data
#' @param MBS.id A character string the MBS.id or cusip number current
MBS.id is supported
#' @export
MBS - function(MBS.id = character){
MBS.Conn - gzfile(description = paste(system.file(package
= BondLab),
/BondData/, MBS.id, .rds, sep = ), open
= rb)
MBS - readRDS(MBS.Conn)
return(MBS)
close.connection(MBS.Conn)
}
I have googled this warning and it seems to be triggered when a function
terminates and the connection is open. But, I think the connection function
closes the connection once the object is returned. What am I doing wrong?
Your call to return() exits the function, so the close.connection()
call is never evaluated. Considering using on.exit() to close the
connection, since it will close the connection regardless of how the
function exits (e.g. because of an error).
-Glenn
__
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[R-pkg-devel] Working with connections
Hi All,
I use connections to open and close data folders needed by my package. After
each function closes I get the following warnings (depending on the connection
that has been opened).
10: closing unused connection 3
(/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds)
Below is the connection function that is related to the above warning:
#
#' A connection function to BondData calling MBS cusps
#'
#' Opens a connection to the BondData folder to call MBS cusip data
#' @param MBS.id A character string the MBS.id or cusip number current MBS.id
is supported
#' @export
MBS - function(MBS.id = character){
MBS.Conn - gzfile(description = paste(system.file(package =
BondLab),
/BondData/, MBS.id, .rds, sep = ), open =
rb)
MBS - readRDS(MBS.Conn)
return(MBS)
close.connection(MBS.Conn)
}
I have googled this warning and it seems to be triggered when a function
terminates and the connection is open. But, I think the connection function
closes the connection once the object is returned. What am I doing wrong?
-Glenn
__
R-package-devel@r-project.org mailing list
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Re: [R-pkg-devel] Working with connections
On Sun, Aug 9, 2015 at 8:59 AM, Glenn Schultz glennmschu...@me.com wrote:
Hi All,
I use connections to open and close data folders needed by my package.
After each function closes I get the following warnings (depending on the
connection that has been opened).
10: closing unused connection 3
(/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds)
Below is the connection function that is related to the above warning:
#
#' A connection function to BondData calling MBS cusps
#'
#' Opens a connection to the BondData folder to call MBS cusip data
#' @param MBS.id A character string the MBS.id or cusip number current
MBS.id is supported
#' @export
MBS - function(MBS.id = character){
MBS.Conn - gzfile(description = paste(system.file(package
= BondLab),
/BondData/, MBS.id, .rds, sep = ), open
= rb)
MBS - readRDS(MBS.Conn)
return(MBS)
close.connection(MBS.Conn)
}
I have googled this warning and it seems to be triggered when a function
terminates and the connection is open. But, I think the connection function
closes the connection once the object is returned. What am I doing wrong?
Your call to return() exits the function, so the close.connection()
call is never evaluated. Considering using on.exit() to close the
connection, since it will close the connection regardless of how the
function exits (e.g. because of an error).
-Glenn
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Re: [R-pkg-devel] Working with connections
Hi Hadley,
Thanks for answering. I basically followed what was outlined in Software for
Data Analysis. Although, I must admit it was a little light in this area
(about a paragraph). I will have to do some additional reading/research on the
RDS inside a gz issue. If it is not the correct application then I need to
correct what I am doing.
To the second issue, I am exposing then data via a function to provide data
storage/retrieval flexibility because cusip data for MBS securities can go to
the terabyte. Additionally, in the case of a REMIC (a resecuritization) the
cusip detail is assembled from many objects (a one to many relationship) before
analysis begins.
So, based on the above I was thinking that one could have the data stored
remotely (SQL, etc.) and edit the connection function as needed to point it to
the required cusip data. Is there a better way to do this?
-Glenn
On Aug 09, 2015, at 09:23 AM, Hadley Wickham h.wick...@gmail.com wrote:
Also it's a little strange to put an RDS file _inside_ a gz, since
normally the compression is done internally.
And are you sure you should be exposing this data via a function,
rather than using the regular package data mechanism?
Hadley
On Sun, Aug 9, 2015 at 7:04 AM, Joshua Ulrich josh.m.ulr...@gmail.com wrote:
On Sun, Aug 9, 2015 at 8:59 AM, Glenn Schultz glennmschu...@me.com wrote:
Hi All,
I use connections to open and close data folders needed by my package.
After each function closes I get the following warnings (depending on the
connection that has been opened).
10: closing unused connection 3
(/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/BondData/bondlabMBS4.rds)
Below is the connection function that is related to the above warning:
#
#' A connection function to BondData calling MBS cusps
#'
#' Opens a connection to the BondData folder to call MBS cusip data
#' @param MBS.id A character string the MBS.id or cusip number current
MBS.id is supported
#' @export
MBS - function(MBS.id = character){
MBS.Conn - gzfile(description = paste(system.file(package
= BondLab),
/BondData/, MBS.id, .rds, sep = ), open
= rb)
MBS - readRDS(MBS.Conn)
return(MBS)
close.connection(MBS.Conn)
}
I have googled this warning and it seems to be triggered when a function
terminates and the connection is open. But, I think the connection function
closes the connection once the object is returned. What am I doing wrong?
Your call to return() exits the function, so the close.connection()
call is never evaluated. Considering using on.exit() to close the
connection, since it will close the connection regardless of how the
function exits (e.g. because of an error).
-Glenn
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