R help - Nov 2016 - coursera course - assgnment - error : Error in which(!is.Na(content[["sulfate"]])) : , could not find function "is.Na"

Hello,

I want to try to get all the data of a cloumn namend "sulfate" which
is
not Na.

So I did :

corr <- function(directory, threshold = 0) {

   # lezen van alle bestanden in  de directory

   file_list <-  list.files( directory, pattern = "*.csv",
full.names =
TRUE)

    # lezen van alle bestanden in a loop
   #  1) bepalen van de complete_cases
   #  2) controleren of het hoger/lager is dan de treshold.
   #  3) als het hoger is.
   #     a) lezen van de nitraat en controleren of het geen Na is
   #     b) lezen van de sulfaat en controleren of het geen Na is.
   #     c) als beide geen Na zijn, dan de correlatie bepalen

   for(file in file_list) {
     content <- read.csv(file)
     if (complete.cases(content) > 0) {
       sulfate <- which (!is.Na(content[["sulfate"]]))
       print(sulfate)

     }

     }

   }

but now I see the above error.

What did I do wrong ?

Regards,

Roelof

Hello,

Just read the error message more carefully.
The function name is the (obvious) problem! Try, with all lowercase,

is.na()

Hope this helps,

Rui Barradas

Em 03-11-2016 16:40, Roelof Wobben escreveu:
> Hello,
>
> I want to try to get all the data of a cloumn namend "sulfate"
which is
> not Na.
>
> So I did :
>
> corr <- function(directory, threshold = 0) {
>
>    # lezen van alle bestanden in  de directory
>
>    file_list <-  list.files( directory, pattern = "*.csv",
full.names > TRUE)
>
>     # lezen van alle bestanden in a loop
>    #  1) bepalen van de complete_cases
>    #  2) controleren of het hoger/lager is dan de treshold.
>    #  3) als het hoger is.
>    #     a) lezen van de nitraat en controleren of het geen Na is
>    #     b) lezen van de sulfaat en controleren of het geen Na is.
>    #     c) als beide geen Na zijn, dan de correlatie bepalen
>
>    for(file in file_list) {
>      content <- read.csv(file)
>      if (complete.cases(content) > 0) {
>        sulfate <- which (!is.Na(content[["sulfate"]]))
>        print(sulfate)
>
>      }
>
>      }
>
>    }
>
> but now I see the above error.
>
> What did I do wrong ?
>
> Regards,
>
> Roelof
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

Hello again,

I've just read your code more carefully and I believe you should read 
the help page ?complete.cases and run the examples therein.
Tip: don't compare the return value with 0, it's nonsense.

Rui Barradas

Em 03-11-2016 16:40, Roelof Wobben escreveu:
> Hello,
>
> I want to try to get all the data of a cloumn namend "sulfate"
which is
> not Na.
>
> So I did :
>
> corr <- function(directory, threshold = 0) {
>
>    # lezen van alle bestanden in  de directory
>
>    file_list <-  list.files( directory, pattern = "*.csv",
full.names > TRUE)
>
>     # lezen van alle bestanden in a loop
>    #  1) bepalen van de complete_cases
>    #  2) controleren of het hoger/lager is dan de treshold.
>    #  3) als het hoger is.
>    #     a) lezen van de nitraat en controleren of het geen Na is
>    #     b) lezen van de sulfaat en controleren of het geen Na is.
>    #     c) als beide geen Na zijn, dan de correlatie bepalen
>
>    for(file in file_list) {
>      content <- read.csv(file)
>      if (complete.cases(content) > 0) {
>        sulfate <- which (!is.Na(content[["sulfate"]]))
>        print(sulfate)
>
>      }
>
>      }
>
>    }
>
> but now I see the above error.
>
> What did I do wrong ?
>
> Regards,
>
> Roelof
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

> On Nov 3, 2016, at 9:40 AM, Roelof Wobben <r.wobben at home.nl>
wrote:
> 
> Hello,
> 
> I want to try to get all the data of a cloumn namend "sulfate"
which is not Na.
> 
> So I did :
> 
> corr <- function(directory, threshold = 0) {
> 
>  # lezen van alle bestanden in  de directory
> 
>  file_list <-  list.files( directory, pattern = "*.csv",
full.names = TRUE)
> 
>   # lezen van alle bestanden in a loop
>  #  1) bepalen van de complete_cases
>  #  2) controleren of het hoger/lager is dan de treshold.
>  #  3) als het hoger is.
>  #     a) lezen van de nitraat en controleren of het geen Na is
>  #     b) lezen van de sulfaat en controleren of het geen Na is.
>  #     c) als beide geen Na zijn, dan de correlatie bepalen
> 
>  for(file in file_list) {
>    content <- read.csv(file)
>    if (complete.cases(content) > 0) {
>      sulfate <- which (!is.Na(content[["sulfate"]]))
>      print(sulfate)
> 
>    }
> 
>    }
> 
>  }
> 
> but now I see the above error.
> 
> What did I do wrong ?
You are sending a request for academic assistance to a mailing list that
specifically describes an expectation that you will use the academic assistance
resources are your institution of higher learning. Since Coursera is a fee-based
enterprise now, I would expect that they have some sort of web-page interface
for collaborating with your coursemates.

For this and other advice about constructing non-homework questions likely to
get answers on Rhelp, you should read the Posting Guide whose link is appended
to every distributed post to Rhelp.

-- 
David
> 
> Regards,
> 
> Roelof
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
David Winsemius
Alameda, CA, USA