Can't compute mean of dataset although proceed like explained

General
#1

Hi

I want to compute the mean of a dataset. I tried it according to the introduction I got but it doesn't work.
I proceeded as follows:
mean(dataframe$column I want compute the mean of)
It was written that the object wasn't found.

I loaded the dataset before whilst clicking on "environment" and then "import dataset". However by "setwd" it didn't work. Maybe it has something to do with this.

The values in the respective column are all numbers by the way.

Does anybody know how this is solvable?

#2 
# if not a standard built-in dataset, like mtcars, load the library that has it
library(palmerpenguins)
# bring the data into namespace
data("penguins")
# inspect
head(penguins)
#> # A tibble: 6 × 8
#>   species island bill_length_mm bill_depth_mm flipper_length_… body_mass_g sex  
#>   <fct>   <fct>           <dbl>         <dbl>            <int>       <int> <fct>
#> 1 Adelie  Torge…           39.1          18.7              181        3750 male 
#> 2 Adelie  Torge…           39.5          17.4              186        3800 fema…
#> 3 Adelie  Torge…           40.3          18                195        3250 fema…
#> 4 Adelie  Torge…           NA            NA                 NA          NA <NA> 
#> 5 Adelie  Torge…           36.7          19.3              193        3450 fema…
#> 6 Adelie  Torge…           39.3          20.6              190        3650 male 
#> # … with 1 more variable: year <int>
# check for NA values
sum(is.na(penguins))
#> [1] 19
# there are columns with than one, so use na.rm = TRUE
# find numeric columns
str(penguins)
#> tibble [344 × 8] (S3: tbl_df/tbl/data.frame)
#>  $ species          : Factor w/ 3 levels "Adelie","Chinstrap",..: 1 1 1 1 1 1 1 1 1 1 ...
#>  $ island           : Factor w/ 3 levels "Biscoe","Dream",..: 3 3 3 3 3 3 3 3 3 3 ...
#>  $ bill_length_mm   : num [1:344] 39.1 39.5 40.3 NA 36.7 39.3 38.9 39.2 34.1 42 ...
#>  $ bill_depth_mm    : num [1:344] 18.7 17.4 18 NA 19.3 20.6 17.8 19.6 18.1 20.2 ...
#>  $ flipper_length_mm: int [1:344] 181 186 195 NA 193 190 181 195 193 190 ...
#>  $ body_mass_g      : int [1:344] 3750 3800 3250 NA 3450 3650 3625 4675 3475 4250 ...
#>  $ sex              : Factor w/ 2 levels "female","male": 2 1 1 NA 1 2 1 2 NA NA ...
#>  $ year             : int [1:344] 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 ...
# create data frame of only numeric colunmns
dat <- penguins[,-c(1,2,7)]
# find means of one numeric column
mean(dat$bill_depth_mm)
#> [1] NA
# now with na.rm = TRUE
mean(dat$bill_length_mm, na.rm = TRUE)
#> [1] 43.92193
# find means of each numeric column
# convert to matrix
colMeans(dat, na.rm = TRUE)
#>    bill_length_mm     bill_depth_mm flipper_length_mm       body_mass_g 
#>          43.92193          17.15117         200.91520        4201.75439 
#>              year 
#>        2008.02907

# if the data is NOT in a package, but in a csv file

# EXAMPLE, use the location of your data; full pathname not needed if the file
# is in the current working director
YOUR_CSV <- read.csv("/usr/local/lib/R/site-library/palmerpenguins/extdata/penguins.csv")
# proceed as before with YOUR_CSV in place of penguins
#3

Thank you for your answer.

Unfortunately it didn't work. It is a csv data file and I tried your advice. I received the notification:

Error in read.table(file = file, header = header, sep = sep, quote = quote, :
object 'pruefung.csv' not found

If I insert the full pathname it says:

Error: unexpected input in "pruefung.csv <- read.csv(C:"

It just works if I click on Environment -> import dataset it shows the data in a table. Isn't it the same as if I made YOUR_CSV <- read.csv?

Since the first raw contains the names of the variables I furthermore wrote header = True.

#4

The full pathname, including the drive, C, part must be within the quote mark pair.

#5

Blockquote
The full pathname, including the drive, C , part must be within the quote mark pair.

The following notification showed up: Error: '\U' used without hex digits in character string starting ""C:\U"

#6

On windows you have to either double up on the slashes or reverse them

"C:\\Users\\somewhere\\"
"C:/Users/somewhere/"
1 Like
#7

Blockquote
On windows you have to either double up on the slashes or reverse them

"C:\\Users\\somewhere\\"
"C:/Users/somewhere/"

It seems to be stubborn. When I did this the following notification appeared:

Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
cannot open file 'C:/datapath permission denied

#8

Can you confirm outside of R whether you do or do not have permissions on the folder in question ?

#9

I have permission for the folder. I can open it without being asked for a password or anything like this.

#10

Have you tried going to press CTR + SHIFT + H to set your working directory, chose the folder where you file is located, then in r type dir() to get an overview of the files in that directory and copy + paste the name so you know that there are no typos.

As others have said, it might be because of a restriction to open the folder, have you tried another folder?

#11

BlockquoteHave you tried going to press CTR + SHIFT + H to set your working directory, chose the folder where you file is located, then in r type dir() to get an overview of the files in that directory and copy + paste the name so you know that there are no typos.
As others have said, it might be because of a restriction to open the folder, have you tried another folder?

I tried what you said without success. The folder opens but it's written no items match your search.

What I don't understand: When I went to import dataset it worked and the data are shown in a table (But not possible to compute the mean). Is it a difference to do it like this instead of the other ways discussed here?