Re: How can I do a "grep -v" equivalent in Import[]?
- To: mathgroup at smc.vnet.net
- Subject: [mg91806] Re: How can I do a "grep -v" equivalent in Import[]?
- From: David Bailey <dave at Remove_Thisdbailey.co.uk>
- Date: Mon, 8 Sep 2008 06:10:29 -0400 (EDT)
- References: <g9t6mq$j8s$1@smc.vnet.net>
Jason Ledbetter wrote:
> Folk,
> I have some data that is column formatted with a dual line header every few
> lines; there may also be a variable number of lines between each header
> output. The first line is readily identifiable with say "grep ^FOO", but the
> second line in the header has white space at the beginning.
>
> So what I need to do is the equivalent of "grep -v" to get rid of the
> headers. My ultimate goal is to create a named List[] variable for each
> "column" in the data, but I need to get rid of the headers.
>
> Alternatively, I could regex match on the lines I DO want I think.. just
> trying to wrap my head around how to do this in Mathematica.
> For example, "egrep '^[0-9]+' foo.txt" gets me what I need in most shells...
> I'd just like mathematica to do the same on import.
>
> Do I need to process the import procedurally and dump the data I want into a
> new Table[]?
>
> I've been able to figure out how to get columnar data out of the import
> using "foo=data[[All,{1}]" and so on (e.g., first column in the data)... I
> just need to pre-filter the headers out.
>
> I apologize for the junior level of the question. :/
>
> Thanks!
>
> -jbl
>
>
I think that if you post a TINY example of your input file, together
with the corresponding output that you wish to obtain, someone will give
you an answer. As it is, your question is a bit vague.
David Bailey
http://www.dbaileyconsultancy.co.uk
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