could not find function "as.party.Weka_tree" - r

I'm struggling with an error message that I don't understand. I'm doing some decision trees and everything goes fine, until I try to plot it
plot(as.party.Weka_tree(CostSensitive_Tree))
which gives this error:
Error in h(simpleError(msg, call)) :
error in evaluating the argument 'x' in selecting a method for function 'plot': could not find function "as.party.Weka_tree"
I checked multiple times with help.search("as.party.Weka_tree")and the package (
partykit) is installed, what could be the cause of this error?
Thanks!

First, you need to make sure that the package is loaded, i.e., library("partykit"). Second, you should not call the S3 method directly but just say as.party(CostSensitive_Tree). Internally the as.party() generic function then dispatches to the as.party.Weka_tree() method but the latter should not be called directly.

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Warning message within R function seems to make the function not work?

Using the syuzhet package in R, the following works but returns a warning message:
object <- get_text_as_string("path/name.txt")
When I put this in a function, it returns the same warning error but does NOT change the value of object:
gen <- function(file){
object <- get_text_as_string(file)
}
gen("path/name.txt")
This is the warning message, if it matters:
Warning message:
In readLines(path_to_file) :
incomplete final line found on 'path/name.txt'
...but again, I get that from get_text_as_string() when used outside of the function, but it DOES change the value of object.
Anyone have any advice? There must be something I don't understand about functions?
(I've looked for similar questions/answers, if I've missed the right one I'd be happy to just be directed there.)

Impulse response function in R not generating plots due to not applicable method

i try to run a IRF analysis on a Data frame with 3 variables:
Time Series Data Frame
Where Model1 looks like this:
Model1
library(vars) and library(varEst) are used
However, when i try
plot(varp.irfs, plot.type="multiple")
following error appears:
Error in h(simpleError(msg, call)) :
error in evaluating the argument 'x' in selecting a method for function 'plot': object 'varp.irfs' not found
Which refers to a missing object varp.irfs.
Also, if i try alternatives like:
plot(irf(Model1,n.ahead=10))
I get similar error message:
Error in h(simpleError(msg, call)) :
error in evaluating the argument 'x' in selecting a method for function 'plot': no applicable method for 'irf' applied to an object of class "varest"
Solution - as expected was independent of any data examples. The library (vars) has to be loaded singularly, so no other libary uses same function. So disabling and enabling libraries in multiple code runs was the solution.

Suppressing error messages from external functions

I am using the function FixedPoint() from the package FixedPoint for some computations in R. Even if a fixed point of some function cannot be found, FixedPoint() still returns output (indicating the error) and, in addition, returns an error message. I want to suppress any such additional error messages from being printed. Neither try(), nor suppressWarnings(), nor suppressMessages() seem to work. Please find an example below that produces such an additional error message.
library(FixedPoint)
ell=0.95
delta=0.1
r=0.1
lambda=1
tH=1
tL=0.5
etaL=1
etaH=1
sys1=function(y){
A=y[1]
B=y[2]
TA=(etaM*(1-exp(-(lambda*A+lambda*(A+B)+2*delta)*tL))-2*lambda*A^2-lambda*A*B)/2/delta
TB=(etaM*exp(-(lambda*A+lambda*(A+B)+2*delta)*tL)*(1-exp(-(lambda*(A+B)+2*delta)*(tH-tL)))-lambda*B^2-lambda*A*B)/2/delta
return(c(TA,TB))
}
FixedPoint(sys1,c(1.90,0.04))
This seems to work:
cc <- capture.output(ff <- FixedPoint(sys1,c(1.90,0.04)),type="message")
where ff now holds the output you want. (Alternately, you could wrap capture.output(...) in invisible() rather than assigning its return value to a variable.)
The problem seems to be that the error message emanates from an un-silence-d try() clause within the package code.

methylSigCalc function error

Trying to use the latest version of methylSig package (0.3.2), and getting an error when using the methylSigCalc function.
I get a cryptic error message after it figures out the number of loci:
Total number of bases: 2.59m
Error in result[, 3] : subscript out of bounds”
I tried running the code of the methylSigCalc function line by line, and the first error I encounter is when it gets to the methylSig_dataProcess function (below is the error after specifying just one core to try to get a useful error message):
Error in do.call(rbind, lapply(which(validLoci),
methylSig_dataProcess, : error in evaluating the argument 'args' in
selecting a method for function 'do.call': Error in match.fun(FUN) :
object 'methylSig_dataProcess' not found
It does seem that methylSig_dataProcess is now missing from the package.
Any suggestions on where I might be going wrong?
Many thanks,
gogatea

tryCatch does not catch an error if called though RScript

I'm facing a strange issue in R.
Consider the following code (a really simplified version of the real code but still having the problem) :
library(timeSeries)
tryCatch(
{
specificWeekDay <- 2
currTs <- timeSeries(c(1,2),c('2012-01-01','2012-01-02'),
format='%Y-%m-%d',units='A')
# just 2 dates out of range
start <- time(currTs)[2]+100*24*3600
end <- time(currTs)[2]+110*24*3600
# this line returns an empty timeSeries
currTs <- window(currTs,start=start,end=end)
message("Up to now, everything is OK")
# this is the line with the uncatchable error
currTs[!(as.POSIXlt(time(currTs))$wday %in% specificWeekDay),] <- NA
message("I'm after the bugged line !")
},error=function(e){message(e)})
message("End")
When I run that code in RGui, I correctly get the following output:
Up to now, everything is OK
error in evaluating the argument 'i' in
selecting a method for function '[<-': Error in
as.POSIXlt.numeric(time(currTs)) : 'origin' must be supplied
End
Instead, when I run it through RScript (in windows) using the following line:
RScript.exe --vanilla "myscript.R"
I get this output:
Up to now, everything is OK
Execution interrupted
It seems like RScript crashes...
Any idea about the reason?
Is this a timeSeries package bug, or I'm doing something wrong ?
If the latter, what's the right way to be sure to catch all the errors ?
Thanks in advance.
EDIT :
Here's a smaller example reproducing the issue that doesn't use timeSeries package. To test it, just run it as described above:
library(methods)
# define a generic function
setGeneric("foo",
function(x, ...){standardGeneric("foo")})
# set a method for the generic function
setMethod("foo", signature("character"),
function(x) {x})
tryCatch(
{
foo("abc")
foo(notExisting)
},error=function(e)print(e))
It seems something related to generic method dispatching; when an argument of a method causes an error, the dispatcher cannot find the signature of the method and conseguently raises an exception that tryCatch function seems unable to handle when run through RScript.
Strangely, it doesn't happen for example with print(notExisting); in that case the exception is correctly handled.
Any idea about the reason and how to catch this kind of errors ?
Note:
I'm using R-2.14.2 on Windows 7
The issue is in the way the internal C code implementing S4 method dispatch tries to catch and handle some errors and how the non-interactive case is treated in this approach. A work-around should be in place in R-devel and R-patched soon.
Work-around now committed to R-devel and R-patched.
Information about tryCatch() [that the OP already knew and used but I didn't notice]
I think you are missing that your tryCatch() is not doing anything special with the error, hence you are raising an error in the normal fashion. In interactive use the error is thrown and handled in the usual fashion, but an error inside a script run in a non-interactive session (a la Rscript) will abort the running script.
tryCatch() is a complex function that allows the potential to trap and handle all sorts of events in R, not just errors. However by default it is set up to mimic the standard R error handling procedure; basically allow the error to be thrown and reported by R. If you want R to do anything other than the basic behaviour then you need to add a specific handler for the error:
> e <- simpleError("test error")
> tryCatch(foo, error = function(e) e,
+ finally = writeLines("There was a problem!"))
There was a problem!
<simpleError in doTryCatch(return(expr), name, parentenv, handler): object 'foo'
not found>
I suggest you read ?tryCatch in more detail to understand better what it does.
An alternative is to use try(). To modify your script I would just do:
# this is the line with the uncatchable error
tried <- try(currTs[!(as.POSIXlt(time(currTs))$wday %in% specificWeekDay),] <- NA,
silent = TRUE)
if(inherits(tried, "try-error")) {
writeLines("There was an error!")
} else {
writeLines("Everything worked fine!")
}
The key bit is to save the object returned from try() so you can test the class, and to have try() operate silently. Consider the difference:
> bar <- try(foo)
Error in try(foo) : object 'foo' not found
> bar <- try(foo, silent = TRUE)
> class(bar)
[1] "try-error"
Note that in the first call above, the error is caught and reported as a message. In the second, it is not reported. In both cases an object of class "try-error" is returned.
Internally, try() is written as a single call to tryCatch() which sets up a custom function for the error handler which reports the error as a message and sets up the returned object. You might wish to study the R code for try() as another example of using tryCatch().

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