Error could not find function in R

Question

This is meant to be a FAQ question  so please be as complete as possible  The answer is a community answer  so feel free to edit if you think something is missing  This question was discussed and approved on meta   I am using R and tried some function but I got following error message  Error  could not find function  quot some function quot   This question comes up very regularly  When you get this type of error in R  how can you solve it

User · Answer

If this occurs while you check your package (R CMD check), take a look at your NAMESPACE.

You can solve this by adding the following statement to the NAMESPACE:

exportPattern("^[^\\\\.]")

This exports everything that doesn't start with a dot ("."). This allows you to have your hidden functions, starting with a dot:

.myHiddenFunction <- function(x) cat("my hidden function")

User · Answer

I can usually resolve this problem when a computer is under my control  but it s more of a nuisance when working with a grid   When a grid is not homogenous  not all libraries may be installed  and my experience has often been that a package wasn t installed because a dependency wasn t installed   To address this  I check the following    Is Fortran installed   Look for  gfortran    This affects several major packages in R  Is Java installed   Are the Java class paths correct  Check that the package was installed by the admin and available for use by the appropriate user   Sometimes users will install packages in the wrong places or run without appropriate access to the right libraries    libPaths   is a good check  Check ldd results for R  to be sure about shared libraries It s good to periodically run a script that just loads every package needed and does some little test   This catches the package issue as early as possible in the workflow   This is akin to build testing or unit testing  except it s more like a smoke test to make sure that the very basic stuff works  If packages can be stored in a network-accessible location  are they   If they cannot  is there a way to ensure consistent versions across the machines    This may seem OT  but correct package installation includes availability of the right version   Is the package available for the given OS   Unfortunately  not all packages are available across platforms   This goes back to step 5   If possible  try to find a way to handle a different OS by switching to an appropriate flavor of a package or switch off the dependency in certain cases    Having encountered this quite a bit  some of these steps become fairly routine   Although  7 might seem like a good starting point  these are listed in approximate order of the frequency that I use them

User · Answer

You may be able to fix this error by name spacing    the function call   comparison cloud colors   c  red    green    max words   100    to  wordcloud  comparison cloud colors   c  red    green    max words   100

User · Answer

I got the same  error  I was running version  99xxx  I checked for updates from help menu and updated My RStudio to 1 0x  then the error did not come  So simple solution  just update your R Studio

User · Answer

Rdocumentation org has a very handy search function that - among other things - lets you find functions - from all the packages on CRAN  as well as from packages from Bioconductor and GitHub

User · Answer

This error can occur even if the name of the function is valid if some mandatory arguments are missing  i e you did not provide enough arguments   I got this in an Rcpp context  where I wrote a C   function with optionnal arguments  and did not provided those arguments in R  It appeared that optionnal arguments from the C   were seen as mandatory by R  As a result  R could not find a matching function for the correct name but an incorrect number of arguments   Rcpp Function   SEXP RcppFunction arg1  arg2 0     R Calls   RcppFunction 0  raises the error RcppFunction 0  0  does not

User · Answer

If you are using parallelMap you ll need to export custom functions to the slave jobs  otherwise you get an error  could not find function     If you set a non-missing level on parallelStart the same argument should be passed to parallelExport  else you get the same error  So this should be strictly followed   parallelStart mode     lt your mode here gt    N  level     lt task level gt    parallelExport   lt myfun gt    level     lt task level gt

User · Answer

Another problem  in the presence of a NAMESPACE  is that you are trying to run an unexported function from package foo   For example  contrived  I know  but     gt  mod  lt - prcomp USArrests  scale   TRUE   gt  plot prcomp mod  Error  could not find function  plot prcomp    Firstly  you shouldn t be calling S3 methods directly  but lets assume plot prcomp was actually some useful internal function in package foo  To call such function if you know what you are doing requires the use of      You also need to know the namespace in which the function is found  Using getAnywhere   we find that the function is in package stats    gt  getAnywhere plot prcomp  A single object matching    plot prcomp    was found It was found in the following places   registered S3 method for plot from namespace stats   namespace stats with value  function  x  main   deparse substitute x          screeplot default x  main   main        lt environment  namespace stats gt    So we can now call it directly using    gt  stats   plot prcomp mod    I ve used plot prcomp just as an example to illustrate the purpose  In normal use you shouldn t be calling S3 methods like this  But as I said  if the function you want to call exists  it might be a hidden utility function for example   but is in a namespace  R will report that it can t find the function unless you tell it which namespace to look in   Compare this to the following  stats  plot prcomp The above fails because while stats uses plot prcomp  it is not exported from stats as the error rightly tells us      Error   plot prcomp  is not an exported object from  namespace stats    This is documented as follows      pkg  name returns the value of the exported variable name in namespace pkg  whereas pkg   name returns the value of the internal variable name

User · Answer

There are a few things you should check     Did you write the name of your function correctly  Names are case sensitive  Did you install the package that contains the function  install packages  thePackage    this only needs to be done once  Did you attach that package to the workspace    require thePackage  or library thePackage   this should be done every time you start a new R session  Are you using an older R version where this function didn t exist yet    If you re not sure in which package that function is situated  you can do a few things    If you re sure you installed and attached loaded the right package  type help search  some function   or   some function to get an information box that can tell you in which package it is contained  find and getAnywhere can also be used to locate functions  If you have no clue about the package  you can use findFn in the sos package as explained in this answer  RSiteSearch  some function   or searching with rdocumentation or rseek are alternative ways to find the function    Sometimes you need to use an older version of R  but run code created for a newer version  Newly added functions  eg hasName in R 3 4 0  won t be found then  If you use an older R version and want to use a newer function  you can use the package backports to make such functions available  You also find a list of functions that need to be backported on the git repo of backports  Keep in mind that R versions older than R3 0 0 are incompatible with packages built for R3 0 0 and later versions

User · Answer

I had the error     Error  could not find function some function   happen when doing R CMD check of a package I was making with RStudio   I found adding  exportPattern       to the NAMESPACE file did the trick   As a sidenote  I had initially configured RStudio to use ROxygen to make the documentation -- and selected the configuration where ROxygen would write my NAMESPACE file for me  which kept erasing my edits   So  in my instance I unchecked NAMESPACE from the Roxygen configuration and added exportPattern      to NAMESPACE to solve this error

[r] Error: could not find function ... in R

Examples related to r

Examples related to function

Examples related to error-handling

Examples related to r-faq