[R] Extract student ID that match certain criteria

[roslinazairimah zakaria]

Hi Bert,

Thank you so much for your help.  However I don't really sure what is the
use of y values.  Can we do without it?

x <- as.character(FKASA$STUDENT_ID)
y <- c(1,786)
My.Data <- data.frame (x,y)

My.Data[grep("^AA14", My.Data$x), ]

I got the following data:

          x   y
1   AA14068   1
7   AA14090   1
11  AA14099   1
14  AA14012 786
15  AA14039   1
22  AA14251 786

On Mon, Mar 13, 2017 at 11:51 AM, Bert Gunter <bgunter.4567 at gmail.com>
wrote:

> 1. Your code is incorrect. All entries are character strings and must be
> quoted.
>
> 2. See ?grep  and note in particular (in the "Value" section):
>
> "grep(value = TRUE) returns a character vector containing the selected
> elements of x (after coercion, preserving names but no other
> attributes)."
>
>
> 3. While the fixed = TRUE option will work here, you may wish to learn
> about "regular expressions", which can come in very handy for
> character string manipulation tasks. ?regex in R has a terse, but I
> have found comprehensible, discussion. There are many good gentler
> tutorials on the web, also.
>
>
> Cheers,
> Bert
>
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along
> and sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>
>
> On Sun, Mar 12, 2017 at 8:32 PM, roslinazairimah zakaria
> <roslinaump at gmail.com> wrote:
> > Dear r-users,
> >
> > I have this list of student ID,
> >
> > dt <- c(AA14068, AA13194, AE11054, AA12251, AA13228, AA13286, AA14090,
> > AA13256, AA13260, AA13291, AA14099, AA15071, AA13143, AA14012, AA14039,
> > AA15018, AA13234, AA13149, AA13282, AA13218)
> >
> > and I would like to extract all student of ID AA14... only.
> >
> > I search and tried substrt, subset and select but it fail.
> >
> >  substr(FKASA$STUDENT_ID, 2, nchar(string1))
> > Error in nchar(string1) : 'nchar()' requires a character vector
> >> subset(FKASA, STUDENT_ID=="AA14" )
> >  [1] FAC_CODE    FACULTY     STUDENT_ID  NAME        PROGRAM     KURSUS
> >  CGPA        ACT_SS      ACT_VAL     ACT_CS      ACT_LED     ACT_PS
> >  ACT_IM
> > [14] ACT_ENT     ACT_CRE     ACT_UNI     ACT_VOL...
> >
> > Thank you so much for your help.
> >
> > How do I do it?
> > --
> > *Roslinazairimah Zakaria*
> > *Tel: +609-5492370; Fax. No.+609-5492766*
> >
> > *Email: roslinazairimah at ump.edu.my <roslinazairimah at ump.edu.my>;
> > roslinaump at gmail.com <roslinaump at gmail.com>*
> > Faculty of Industrial Sciences & Technology
> > University Malaysia Pahang
> > Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
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> > 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.
>



-- 
*Roslinazairimah Zakaria*
*Tel: +609-5492370; Fax. No.+609-5492766*

*Email: roslinazairimah at ump.edu.my <roslinazairimah at ump.edu.my>;
roslinaump at gmail.com <roslinaump at gmail.com>*
Faculty of Industrial Sciences & Technology
University Malaysia Pahang
Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia

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