I would like to preface this by saying that I am new to R, so I would ask
that you be patient and thorough, so that I'm not completely clueless. I am
trying to convert a list to numeric so that I can perform computations on it
(specifically mean-center the variable), but I am running into problems. I
have imported the data set into "task" (data frame). The data frame
is made
of factors with variable names in the first row. I am running a loop to set
a variable equal to a column in the data frame. Here is an example of my
problem:
for (i in 1:dim(task)[2]){
predictor.loop <- c(task[i])
predictor.loop.mc <- predictor.loop - mean(predictor.loop, na.rm=T)
}
I get the following error:
Error in predictor.loop - mean(predictor.loop, na.rm = T) :
non-numeric argument to binary operator
In addition: Warning message:
In mean.default(predictor.loop, na.rm = T) :
argument is not numeric or logical: returning NA
The column is entirely made up of numerical data, except for the header,
which is a string. My problem is that I receive an error because the
predictor.loop variable is not numerical, so I need to find a way to convert
it. I tried using:
predictor.loop <- c(as.numeric(task[i]))
But I get the following error: "Error: (list) object cannot be coerced to
type 'double'"
If I call the variable, I can assign it to a numerical list (e.g., predictor
loop <- task$variablename), but since I am assigning the variable in a loop,
I have to find another way as the variable name would have to change in each
loop iteration. Any help would be greatly appreciated. Thanks!
--
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it appears that what you really want is to use: task[[i]] instead of task[i] b On Nov 1, 2009, at 11:04 PM, dadrivr wrote:> > I would like to preface this by saying that I am new to R, so I > would ask > that you be patient and thorough, so that I'm not completely > clueless. I am > trying to convert a list to numeric so that I can perform > computations on it > (specifically mean-center the variable), but I am running into > problems. I > have imported the data set into "task" (data frame). The data frame > is made > of factors with variable names in the first row. I am running a > loop to set > a variable equal to a column in the data frame. Here is an example > of my > problem: > > for (i in 1:dim(task)[2]){ > predictor.loop <- c(task[i]) > predictor.loop.mc <- predictor.loop - mean(predictor.loop, na.rm=T) > } > > I get the following error: > Error in predictor.loop - mean(predictor.loop, na.rm = T) : > non-numeric argument to binary operator > In addition: Warning message: > In mean.default(predictor.loop, na.rm = T) : > argument is not numeric or logical: returning NA > > The column is entirely made up of numerical data, except for the > header, > which is a string. My problem is that I receive an error because the > predictor.loop variable is not numerical, so I need to find a way to > convert > it. I tried using: > predictor.loop <- c(as.numeric(task[i])) > But I get the following error: "Error: (list) object cannot be > coerced to > type 'double'" > > If I call the variable, I can assign it to a numerical list (e.g., > predictor > loop <- task$variablename), but since I am assigning the variable in > a loop, > I have to find another way as the variable name would have to change > in each > loop iteration. Any help would be greatly appreciated. Thanks! > -- > View this message in context: http://old.nabble.com/convert-list-to-numeric-tp26155039p26155039.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Can you at least provide an 'str' of the 'task' object (not sure if it is a dataframe; you said a 'list') so that we know what it looks like. It would also be helpful if you would provide a subset of the data that we could try out a script on it. The best way would be to post the first 10 or so rows (and limit columns it more that 10 or so). A convenient way is to : dput(task[1:10,]) and then cut/paste the result into your email. On Sun, Nov 1, 2009 at 8:04 PM, dadrivr <dadrivr at gmail.com> wrote:> > I would like to preface this by saying that I am new to R, so I would ask > that you be patient and thorough, so that I'm not completely clueless. ?I am > trying to convert a list to numeric so that I can perform computations on it > (specifically mean-center the variable), but I am running into problems. ?I > have imported the data set into "task" (data frame). ?The data frame is made > of factors with variable names in the first row. ?I am running a loop to set > a variable equal to a column in the data frame. ?Here is an example of my > problem: > > for (i in 1:dim(task)[2]){ > predictor.loop <- c(task[i]) > predictor.loop.mc <- predictor.loop - mean(predictor.loop, na.rm=T) > } > > I get the following error: > Error in predictor.loop - mean(predictor.loop, na.rm = T) : > ?non-numeric argument to binary operator > In addition: Warning message: > In mean.default(predictor.loop, na.rm = T) : > ?argument is not numeric or logical: returning NA > > The column is entirely made up of numerical data, except for the header, > which is a string. ?My problem is that I receive an error because the > predictor.loop variable is not numerical, so I need to find a way to convert > it. ?I tried using: > predictor.loop <- c(as.numeric(task[i])) > But I get the following error: "Error: (list) object cannot be coerced to > type 'double'" > > If I call the variable, I can assign it to a numerical list (e.g., predictor > loop <- task$variablename), but since I am assigning the variable in a loop, > I have to find another way as the variable name would have to change in each > loop iteration. ?Any help would be greatly appreciated. ?Thanks! > -- > View this message in context: http://old.nabble.com/convert-list-to-numeric-tp26155039p26155039.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > 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 that you are trying to solve?