On May 31, 2010, at 7:51 PM, Kevin Burnham wrote:
I am trying to import a series of text files generated by stimulus
presentation software. The problem that I am having is that the
number of
rows I need to skip is not fixed (depending on subject's pretest
behavior)
nor is the first row of the data I want always the same (the stimuli
were
presented in random order). So I need to bring in the .txt file
(using
readLines?), look for the row containing the text "Begin Main" (see
exact
row below) and start reading data to a table from that point.
[13] "Main Group\t1000\tBegin Main\tBegin Main\tBegin Main\t\t
\tPressed\t(any response)\tC\t25860\t\t\t\t\t"
I would also like it to ignore the row:
[173] "Main Group\t1000\tBreak\tBreak\
tpause3\t\t \tPressed\t(any response)\tC\t47610\t\t\t\t\t"
which will always be the same number of rows after the "Begin Main"
row.
txt <- "blah
blahe
blah
blah
Main Group\t1000\tBegin Main\tBegin Main\tBegin Main\t\t
\tPressed\t(any response)\tC\t25860\t\t\t\t\t
more blah after blank line
uy
ytre
jhgf
Main Group\t1000\tBreak\tBreak\
tpause3\t\t \tPressed\t(any response)\tC\t47610\t\t\t\t\t
uytr
hgfd"
# ___end setup input______________
> bring.in <- readLines(textConnection(txt))
> grep("\\tBegin Main", bring.in)
[1] 5
> grep("Main Group\\t1000", bring.in)
[1] 5 12
> length.vec <- grep("Main Group\\t1000", bring.in)
> length.vec[2] - length.vec[1]
[1] 7
>
# So a vectorized solution would be:
bring.in[grep("\\tBegin Main", bring.in):(
grep("\\tBegin Main", bring.in)+length.vec[2] -
length.vec[1]-1)]
[2] "\tPressed\t(any response)\tC\t25860\t\t\t\t\t"
[3] ""
[4] "more blah after blank line"
[5] "uy"
[6] "ytre"
[7] "jhgf"
bring.in[grep("\\tBegin Main", bring.in):(
grep("\\tBegin Main", bring.in)+length.vec[2] -
length.vec[1]-1)]
--
David Winsemius, MD
West Hartford, CT
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