R - how to make base "merge" function the default one - r

I'm quite an R newbie, so apologizes if mine is a simple question.
I have many R scripts that use the base merge function. Yesterday, I had to install the config library and that completely screwed up the merge function since it's also defined inside congif.
I read this useful post: R - can't merge dataframe after installing config package
but my question here is different.
I can't go through tens of R scripts and replace "merge()" with "base::merge()".
So my very simple question is the following and very similar to what discussed here:
R: 2 functions with the same name in 2 different packages
how can I specify to use the "base::" version of the function "merge()" as default one?
Or - is there a way to not install the "merge()" function contained inside the config package?
Many thanks

The accepted answer to R - can't merge data frame after installing config package directs the user to explicitly reference functions from the config package as config::merge() or config::get().
Another way to address the problem of config masking base::merge() is to load the config package, use it to configure the environment, and then use detach() to remove the package. This will unmask base::merge().
library(config)
# use config functions to set up environment
#
At this point we can show that config::merge is the default by printing the merge() function.
> merge
function (base_config, merge_config)
{
merge_lists(base_config, merge_config, recursive = TRUE)
}
<bytecode: 0x7fcddf5de488>
<environment: namespace:config>
>
To restore base::merge() as the default, we use the detach() function.
detach(package:config)
# at this point base::merge() and base::get() are unmasked
To demonstrate this, we'll print the merge() function again.
> detach(package:config)
> # print merge function to show it is from base package
> merge
function (x, y, ...)
UseMethod("merge")
<bytecode: 0x7fcde7c08e70>
<environment: namespace:base>
>

Related

Choose function to load from an R package

I like using function reshape from the matlab package, but I need then to specify base::sum(m) each time I want to sum the elements of my matrix or else matlab::sum is called, which only sums by columns..
I need loading package gtools to use the rdirichlet function, but then the function gtools::logit masks the function pracma::logit that I like better..
I gess there are no such things like:
library(loadOnly = "rdirichlet", from = "gtools")
or
library(loadEverythingFrom = "matlab", except = "sum")
.. because functions from the package matlab may internaly work on the matlab::sum function. So the latter must be loaded. But is there no way to get this behavior from the point of view of the user? Something that would feel like:
library(pracma)
library(matlab)
library(gtools)
sum <- base::sum
logit <- pracma::logit
.. but that would not spoil your ls() with all these small utilitary functions?
Maybe I need defining my own default namespace?
To avoid spoiling your ls, you can do something like this:
.ns <- new.env()
.ns$sum <- base::sum
.ns$logit <- pracma::logit
attach(.ns)
To my knowledge there is no easy answer to what you want to achieve. The only dirty hack I can think of is to download the source of the packages "matlab", "gtools", "pracma" and delete the offending functions from their NAMESPACE file prior to installation from source (with R CMD INSTALL package).
However, I would recommend using the explicit notation pracma::logit, because it improves readability of your code for other people and yourself in the future.
This site gives a good overview about package namespaces:
http://r-pkgs.had.co.nz/namespace.html

R Functions require package declaration when they are included from another file?

I am writing some data manipulation scripts in R, and I finally decided to create an external .r file and call my functions from there. But it started giving me some problems when I try calling some functions. Simple example:
This one works with no problem:
change_column_names <- function(file,new_columns,seperation){
new_data <- read.table(file, header=TRUE, sep=seperation)
colnames(new_data) <- new_columns
write.table(new_data, file=file, sep=seperation, quote=FALSE, row.names = FALSE)
}
change_column_names("myfile.txt",c("Column1", "Column2", "Cost"),"|")
When I crate a file "data_manipulation.r", and put the above change_column_names function in there, and do this
sys.source("data_manipulation.r")
change_column_names("myfile.txt",c("Column1", "Column2", "Cost"),"|")
it does not work. It gives me could not find function "read.table" error. I fixed it by changing the function calls to util:::read.table and util:::write.table .
But this kinda getting frustrating. Now I have the same issue with the aggregate function, and I do not even know what package it belongs to.
My questions: Which package aggregate belongs to? How can I easily know what packages functions come from? Any cleaner way to handle this issue?
The sys.source() by default evaluates inside the base environment (which is empty) rather than the global environment (where you usually evaluate code). You probably should just be using source() instead.
You can also see where functions come from by looking at their environment.
environment(aggregate)
# <environment: namespace:stats>
For the first part of your question: If you want to find what package a function belongs to, and that function is working properly you can do one of two (probably more) things:
1.) Access the help files
?aggregate and you will see the package it belongs to in the top of the help file.
Another way, is to simply type aggregate without any arguments into the R console:
> aggregate
function (x, ...)
UseMethod("aggregate")
<bytecode: 0x7fa7a2328b40>
<environment: namespace:stats>
The namespace is the package it belongs to.
2.) Both of those functions that you are having trouble with are base R functions and should always be loaded. I was not able to recreate the issue. Try using source instead of sys.source and let me know if it alleviates your error.

N Choose K function in R not working--what am I missing?

I was trying to acquaint myself with R's nChooseK function but I can't get it to work. I thought it was part of the standard setup (i.e. no additional package needed).
Please help. Here is what I tried:
> nChooseK(10,2)
Error: could not find function "nChooseK"
> n<-4;k<-2
> print(nChooseK(n,k))
Error in print(nChooseK(n, k)) : could not find function "nChooseK"
the last one was an example I saw here: R basic nChooseK
The function is in the R.basic package which is not part of the default R installation. You probably meant to use just choose().
As joran mentions the function nChooseK is a part of R.basic. You can tell this from the example you posted by looking at the top of the page:
You'll notice the "R.basic" in the curley braces which tells you that that function is a part of the "R.basic" package. So to use nChooseK you'll first need to load that package
library(R.basic)
If you don't have R.basic installed yet then you'll need to install it
install.packages("R.basic", contriburl="http://www.braju.com/R/repos/")
library(R.basic)
But as noted the choose function in base R does the same thing
choose(37, 12)
#[1] 1852482996
nChooseK(37, 12)
#[1] 1852482996

Data inside a function (package creation)

If I need to use a data set inside a function (as a lookup table) inside of a package I'm creating do I need to explicitly load the data set inside of the function?
The function and the data set are both part of my package.
Is this the correct way to use that data set inside the function:
foo <- function(x){
x <- dataset_in_question
}
or is this better:
foo <- function(x){
x <- data(dataset_in_question)
}
or is there some approach I'm not thinking of that's correct?
There was a recent discussion about this topic (in the context of package development) on R-devel, numerous points of which are relevant to this question:
If only the options you provide are applicable to your example R himself (i.e., Brian Ripley) tells you to do:
foo <- function(x){
data("dataset_in_question")
}
This approach will however throw a NOTE in R CMD check which can be avoided in upcoming versions of R (or currently R devel) by using the globalVariables() function, added by John Chambers
The 'correct' approach (i.e., the one advocated by Brian Ripley and Peter Dalgaard) would be to use the LazyData option for your package. See this section of "Writing R Extensions".
Btw: I do not fully understand how your first approach should work. What should x <- dataset_in_question do? Is dataset_in_question a global Variable or defined previously?
For me it was necessary to use get() additionally to LazyData: true in DESCRIPTION file (see postig by #Henrik point 3) to get rid of the NOTE no visible binding for global variable .... My R version is 3.2.3.
foo <- function(x){
get("dataset_in_question")
}
So LazyData makes dataset_in_question directly accessible (without using data("dataset_in_question", envir = environment())) and get() is to satisfy R CMD check
HTH
One can just place the data set as a .rda file in the R folder as described by Hadley here: http://r-pkgs.had.co.nz/data.html#data-sysdata
Matthew Jockers uses this approach in the syuzhet package for data sets including the bing data set as seen at ~line 452 here: https://github.com/mjockers/syuzhet/blob/master/R/syuzhet.R
bing is not available to the user but is to the package as demonstrated by: syuzhet:::bing
Essentially, the command devtools::use_data(..., internal = TRUE) will set everything up in the way it's needed.

hiding personal functions in R

I have a few convenience functions in my .Rprofile, such as this handy function for returning the size of objects in memory. Sometimes I like to clean out my workspace without restarting and I do this with rm(list=ls()) which deletes all my user created objects AND my custom functions. I'd really like to not blow up my custom functions.
One way around this seems to be creating a package with my custom functions so that my functions end up in their own namespace. That's not particularly hard, but is there an easier way to ensure custom functions don't get killed by rm()?
Combine attach and sys.source to source into an environment and attach that environment. Here I have two functions in file my_fun.R:
foo <- function(x) {
mean(x)
}
bar <- function(x) {
sd(x)
}
Before I load these functions, they are obviously not found:
> foo(1:10)
Error: could not find function "foo"
> bar(1:10)
Error: could not find function "bar"
Create an environment and source the file into it:
> myEnv <- new.env()
> sys.source("my_fun.R", envir = myEnv)
Still not visible as we haven't attached anything
> foo(1:10)
Error: could not find function "foo"
> bar(1:10)
Error: could not find function "bar"
and when we do so, they are visible, and because we have attached a copy of the environment to the search path the functions survive being rm()-ed:
> attach(myEnv)
> foo(1:10)
[1] 5.5
> bar(1:10)
[1] 3.027650
> rm(list = ls())
> foo(1:10)
[1] 5.5
I still think you would be better off with your own personal package, but the above might suffice in the meantime. Just remember the copy on the search path is just that, a copy. If the functions are fairly stable and you're not editing them then the above might be useful but it is probably more hassle than it is worth if you are developing the functions and modifying them.
A second option is to just name them all .foo rather than foo as ls() will not return objects named like that unless argument all = TRUE is set:
> .foo <- function(x) mean(x)
> ls()
character(0)
> ls(all = TRUE)
[1] ".foo" ".Random.seed"
Here are two ways:
1) Have each of your function names start with a dot., e.g. .f instead of f. ls will not list such functions unless you use ls(all.names = TRUE) therefore they won't be passed to your rm command.
or,
2) Put this in your .Rprofile
attach(list(
f = function(x) x,
g = function(x) x*x
), name = "MyFunctions")
The functions will appear as a component named "MyFunctions" on your search list rather than in your workspace and they will be accessible almost the same as if they were in your workspace. search() will display your search list and ls("MyFunctions") will list the names of the functions you attached. Since they are not in your workspace the rm command you normally use won't remove them. If you do wish to remove them use detach("MyFunctions") .
Gavin's answer is wonderful, and I just upvoted it. Merely for completeness, let me toss in another one:
R> q("no")
followed by
M-x R
to create a new session---which re-reads the .Rprofile. Easy, fast, and cheap.
Other than that, private packages are the way in my book.
Another alternative: keep the functions in a separate file which is sourced within .RProfile. You can re-source the contents directly from within R at your leisure.
I find that often my R environment gets cluttered with various objects when I'm creating or debugging a function. I wanted a way to efficiently keep the environment free of these objects while retaining personal functions.
The simple function below was my solution. It does 2 things:
1) deletes all non-function objects that do not begin with a capital letter and then
2) saves the environment as an RData file
(requires the R.oo package)
cleanup=function(filename="C:/mymainR.RData"){
library(R.oo)
# create a dataframe listing all personal objects
everything=ll(envir=1)
#get the objects that are not functions
nonfunction=as.vector(everything[everything$data.class!="function",1])
#nonfunction objects that do not begin with a capital letter should be deleted
trash=nonfunction[grep('[[:lower:]]{1}',nonfunction)]
remove(list=trash,pos=1)
#save the R environment
save.image(filename)
print(paste("New, CLEAN R environment saved in",filename))
}
In order to use this function 3 rules must always be kept:
1) Keep all data external to R.
2) Use names that begin with a capital letter for non-function objects that I want to keep permanently available.
3) Obsolete functions must be removed manually with rm.
Obviously this isn't a general solution for everyone...and potentially disastrous if you don't live by rules #1 and #2. But it does have numerous advantages: a) fear of my data getting nuked by cleanup() keeps me disciplined about using R exclusively as a processor and not a database, b) my main R environment is so small I can backup as an email attachment, c) new functions are automatically saved (I don't have to manually manage a list of personal functions) and d) all modifications to preexisting functions are retained. Of course the best advantage is the most obvious one...I don't have to spend time doing ls() and reviewing objects to decide whether they should be rm'd.
Even if you don't care for the specifics of my system, the "ll" function in R.oo is very useful for this kind of thing. It can be used to implement just about any set of clean up rules that fit your personal programming style.
Patrick Mohr
A nth, quick and dirty option, would be to use lsf.str() when using rm(), to get all the functions in the current workspace. ...and let you name the functions as you wish.
pattern <- paste0('*',lsf.str(), '$', collapse = "|")
rm(list = ls()[-grep(pattern, ls())])
I agree, it may not be the best practice, but it gets the job done! (and I have to selectively clean after myself anyway...)
Similar to Gavin's answer, the following loads a file of functions but without leaving an extra environment object around:
if('my_namespace' %in% search()) detach('my_namespace'); source('my_functions.R', attach(NULL, name='my_namespace'))
This removes the old version of the namespace if it was attached (useful for development), then attaches an empty new environment called my_namespace and sources my_functions.R into it. If you don't remove the old version you will build up multiple attached environments of the same name.
Should you wish to see which functions have been loaded, look at the output for
ls('my_namespace')
To unload, use
detach('my_namespace')
These attached functions, like a package, will not be deleted by rm(list=ls()).

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