[R] using scan to record user's input

[Ken Knoblauch]

Works on the powerpc with source.  I'll verify later on the Mac Intel.
Thank you very much.

ken

Patrick Callier wrote:
> The apple-enter thing works like copy and paste would, as far as I can
> tell (I get a similar bug).  The deal is that it's entering each line
> in one at a time, so the for-loop starts running after the last brace
> and gets as its input the next line sent from the console.
>
> Either one of the solutions you propose (using source or putting it in
> a function) should fix your problem.
>
> Best,
> Pat
>
> On 3/11/07, Ken Knoblauch <knoblauch at lyon.inserm.fr> wrote:
>> I get it on a powerpc Mac, too,
>>
>> > y <- rep(NA, 3)
>> > for (ix in seq( length(y) ) ) {
>> +          y[ix] <- scan( n = 1 )
>> +         }
>> 1: 2
>> Read 1 item
>> 1: 3
>> Read 1 item
>> 1: 4
>> Read 1 item
>> > y
>> [1] 2 3 4
>> > y <- rep(NA, 3)
>> > for (ix in seq( length(y) ) ) {
>> +          y[ix] <- scan( n = 1 )
>> +         }
>> 1: y
>> 1: 5
>> Error in scan(file, what, nmax, sep, dec, quote, skip, nlines,
>> na.strings,  :
>>         scan() expected 'a real', got 'y'
>> +
>>
>> R version 2.4.1 Patched (2007-01-05 r40386)
>> powerpc-apple-darwin8.8.0
>>
>> locale:
>> en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
>>
>> attached base packages:
>> [1] "stats"     "graphics"  "grDevices" "utils"     "datasets"
>> "methods"
>> [7] "base"
>>
>> Thanks.
>>
>> ken
>>
>> Patrick Callier wrote:
>> > Silly question: Are you 'source'-ing this code or copying and pasting
>> > it from somewhere?  I don't have any problems running your above
>> > example on a PPC Mac with almost the same version of R (using
>> > 'source').
>> >
>> > Here's my info:
>> > R version 2.4.1 (2006-12-18)
>> > powerpc-apple-darwin8.8.0
>> >
>> > locale:
>> > en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
>> >
>> > attached base packages:
>> > [1] "stats"     "graphics"  "grDevices" "utils"     "datasets"
>> > "methods"   "base"
>> >
>> > other attached packages:
>> >       MASS KernSmooth
>> >   "7.2-30"  "2.22-19"
>> >
>> > Otherwise, I'm as stumped as you are.
>> >
>> > On 3/11/07, Ken Knoblauch <knoblauch at lyon.inserm.fr> wrote:
>> >> I'm using scan in a script to record a series of responses of the
>> user
>> >> as
>> >> a function
>> >> of some graphs that I put up on the screen.  A toy version would be,
>> >>
>> >> y <- rep(NA, 3)
>> >> for (ix in seq( length(y) ) ) {
>> >>         y[ix] <- scan( n = 1 )
>> >>         }
>> >>
>> >> However, if I include any code after this loop, for example,
>> >> y <- rep(NA, 3)
>> >> for (ix in seq( length(y) ) ) {
>> >>         y[ix] <- scan( n = 1 )
>> >>         }
>> >> y
>> >>
>> >> I get an error after I've entered my first number.
>> >>
>> >> 1: y
>> >> 1: 3
>> >> Error in scan(file, what, nmax, sep, dec, quote, skip, nlines,
>> >> na.strings,  :
>> >>         scan() expected 'a real', got 'y'
>> >>
>> >> scan seems to be trying to read the commands after the loop.  In the
>> >> real
>> >> case,
>> >> the loop is longer and there are more commands after the loop.
>> >> If I have more commands, I get the error right away, before the
>> prompt
>> >> to
>> >> enter a number.
>> >>
>> >> I didn't see anything in the scan help that would allow me to
>> circumvent
>> >> this error.
>> >>
>> >> Can anyone suggest a way to get around this error.
>> >>
>> >> Thank you.
>> >>
>> >> Ken
>> >>
>> >> Here is my info
>> >>
>> >> sessionInfo()
>> >> R version 2.4.1 Patched (2007-01-23 r40561)
>> >> i386-apple-darwin8.8.1
>> >>
>> >> locale:
>> >> C
>> >>
>> >> attached base packages:
>> >> [1] "stats"     "graphics"  "grDevices" "utils"     "datasets"
>> >> "methods"
>> >> [7] "base"
>> >>
>> >> other attached packages:
>> >>     MASS
>> >> "7.2-31"
>> >>
>> >>
>> >> --
>> >> Ken Knoblauch
>> >> Inserm U846
>> >> Institut Cellule Souche et Cerveau
>> >> Département Neurosciences Intégratives
>> >> 18 avenue du Doyen Lépine
>> >> 69500 Bron
>> >> France
>> >> tel: +33 (0)4 72 91 34 77
>> >> fax: +33 (0)4 72 91 34 61
>> >> portable: +33 (0)6 84 10 64 10
>> >> http://www.pizzerialesgemeaux.com/u846/
>> >>
>> >> ______________________________________________
>> >> R-help at stat.math.ethz.ch 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.
>> >>
>> >
>>
>>
>> --
>> Ken Knoblauch
>> Inserm U846
>> Institut Cellule Souche et Cerveau
>> Département Neurosciences Intégratives
>> 18 avenue du Doyen Lépine
>> 69500 Bron
>> France
>> tel: +33 (0)4 72 91 34 77
>> fax: +33 (0)4 72 91 34 61
>> portable: +33 (0)6 84 10 64 10
>> http://www.pizzerialesgemeaux.com/u846/
>>
>>
>


-- 
Ken Knoblauch
Inserm U846
Institut Cellule Souche et Cerveau
Département Neurosciences Intégratives
18 avenue du Doyen Lépine
69500 Bron
France
tel: +33 (0)4 72 91 34 77
fax: +33 (0)4 72 91 34 61
portable: +33 (0)6 84 10 64 10
http://www.pizzerialesgemeaux.com/u846/