regular expression for selection
On 14.11.2011 10:22, Petr PIKAL wrote:
Hi
On 11/14/2011 07:45 PM, Petr PIKAL wrote:
Dear all I am again (as usual) lost in regular expression use for selection.
Here
are my data:
dput(mena)
c("138516_10g_50ml_50c_250utes1_m53.00-_s1.imp",
"138516_10g_50ml_50c_250utes1_m54.00_s1.imp",
"138516_10g_50ml_50c_250utes1_m55.00_s1.imp",
"138516_10g_50ml_50c_250utes1_m56.00_s1.imp",
"138516_10g_50ml_50c_250utes1_m57.00_s1.imp",
"138516_10g_50ml_50c_250utes1_m58.00_s1.imp",
"138516_10g_50ml_50c_250utes1_m59.00_s1.imp")
I want to select only values "m" foolowed by numbers from 53 to 59.
I used
sub("m5.", "", mena)
which correctly selects those m53 - m59 values but, in contrary to my
expectation, it replaced the selected values with specified
replacement -
in that case empty string. What I shall use if I want to get rid of all but m53-m59 from those strings?
Hi Petr,
How about:
grep("m5",mena)
It gives numeric values which tells me that there is a match in each string, but as a result I need only m53-m59 substrings.
gsub(".*_(m5.).*", "\\1", mena)
Uwe Ligges
Regards Petr
Jim
______________________________________________ R-help at r-project.org 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.