[R] Extract student ID that match certain criteria
bgunter.4567 at gmail.com
Mon Mar 13 04:51:47 CET 2017
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
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.
"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" )
>  FAC_CODE FACULTY STUDENT_ID NAME PROGRAM KURSUS
> CGPA ACT_SS ACT_VAL ACT_CS ACT_LED ACT_PS
>  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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