Finding/Replacing "^" character using grep [closed] - r

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Suppose I have a very simple data frame:
symbol <- c("A", "A^","B","C","C^")
df = data.frame(symbol)
Now imagine this is a very large dataframe so that I cannot easily list the rows in which the character "^" appears.
How can I subset the rows with (or without) that character?
Notice that things like:
df[grep("^", df$symbol)
or regular subsetting will not work since the carat "^" is usually used to represent the beggining of a string.
Many thanks

Add fixed to the grep function, as follows:
df[grep("^", df$symbol, fixed=T),]

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The length() function is not returning the right number [closed]

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I working with a csv that has 234 rows. I thought the length() function was supposed to return the number of rows in my csv, but it returns a much larger number. It gives me 1046860. Does the length function not do what I think it does? What is going on?
I just wanted to double check the length and haven't run any other code yet other than setting up my working directory and attaching a file (Cat6 <- read.csv("Category6.csv")).

My variables in my data frame are numbers which are counted as characters [closed]

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Closed 1 year ago.
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In R, I have a variable column of numbers which are being counted as variables. When I do as.numeric() on it I get the "NA caused by coercion" and nothing works.
This is what the code looks like
Volume.x has no NA in it, every single value is a number but it's read as a character and doing the as.numeric() prints a bunch of NA's
We can remove the , and convert to numeric
df1$Volume.x <- as.numeric(gsub(",", "", df1$Volume.x))

How to choose the first "n" elements in R [closed]

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Closed 5 years ago.
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(USING R)
So I imported a data set by using
xcars <- read.csv(file.choose())
and then I chose my data set which was originally an excel file.
So, I have a column named dist (short for displacement) and I want to choose the first 25 entries underneath that column and then plot it on a histogram, so I attempted the following.
carsUpTo25 <- xcars(1:25,)
hist(carsUpTo25$dist)
Of course this didn't work. However, any help on how I would do this would be helpful.
Try this-
hist(xcars[,dist[1:10]])

for loop in data frame in R [closed]

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I am new in R and I would like to ask what is wrong in the following simple command. When i try:
for (k in 1:1){
logdata= logDataset[1:74+k,k]}
logdata collects the values from rows 2:75 of column 1 of the logDataset data frame. But when I use:
logdata=logDataset[1:75,1]
logdata collects correctly the first 75 values of the first column. Why the first command does not work as the second one? How can I use the "for" command for collecting the first 75 values of the first column? Many thanks.

fread() deals with quoted zero-prefixed colum different from read.csv() [closed]

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I have a csv file with quoted numeric column such as "'0001',a\n'0002',b\n'0003',c", for fread(), the first column will be character but for read.csv() the 1st column will be numeric type.
How can I make it work same as read.csv()?
You need to specify the type of the column through argument colClasses, e.g.
fread(..., colClasses = c("character", "character"))`.

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