See
?rle
Start with this:
a1.runs <- rle( a1 )
a1.runs$lengths[ a1.runs$values>0 ]
[1] 3 4
HTH,
Chuck
p.s.
library(fortunes)
fortune(106)
If the answer is parse() you should usually rethink the question.
-- Thomas Lumley
R-help (February 2005)
--
see
?get
On Fri, 13 Jun 2008, [EMAIL PROTECTED] wrote:
Dear R Group:
I have little experience using R and even less experience with control
flow type questions.
See the following code:
a1 = c(0, 1, 1, 1,
0, 0, 0, 0, 0,
0, 0, 1,
1, 1, 1, 0, 0)
for(i in 1:1){
sx <- paste("a",i,sep="")
s <- eval(parse(text = paste("a",i,sep="")))
{g = numeric(length(s))
k = numeric(length(s))
{for (i in 1:length(s))
{for (j in 1:length(s))
ifelse(((j=i)>1),(g[j] = s[j] + s[i]),(k[j] = s[j] + s[i]))
}}
h1 <- hist(g,freq=TRUE)
h <- h1$counts[4]
cat(sx,":", h,"\n",file = "C:/temp/test-beta.txt", append=TRUE)
}}
The output is:
g
[1] 0 2 2 2 0 0 0 0 0 0 0 2 2 2 2 0 0
k
[1] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
h
[1] 7
& a text file, which has:
a1 : 7
k is a by-product of the ifelse statement and is of no interest & g and
h only go part-way to answering my question, which is:
For every time an object i.e. a1 (which is actually a time series) - 0 1
1 1 0 0 0 0 0 0 0 1 1 1 1 0 0 has as value over 0 how long do the
values stay above 0. So in this case a1 has two goups or events where
the value is above zero, the first event lasts for 3 'days' and the
second event lasts for 4 'days'. I have my code telling me that there
was a total of 7 'days' in event or above 0, but what I need to know is
that there were two 'events' and the 1st lasted 3 'days' and the 2nd
lasted '4' days. Essentially I want a text file output to say:
a1.1 : 3
a1.2 : 4
My thinking is that I need to somehow get the code working through each
vector one value at a time and when a value is found to meet the critera
of > 0 R creates a new vector; to use the above example it would come
to the first value >0 and then create the new vector a1.1 = (1,1,1) then
as the next value in the series is 0 it would close this new vector
'a1.1'. It would then continue until it reaches the next value >0 and
then create the vector a1.2 = (1,1,1,1) then again as the next value in
the series is 0 it would close this new vector, and so on.
Then all I need to do is perform a count of '1's in these new vectors to
find how many days they met this criteria of being greater than 0
I hope the above makes sense and I really hope there is someone willing
and able to help. I don't know how to proceed.
Thanks,
Garth
[[alternative HTML version deleted]]
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Charles C. Berry (858) 534-2098
Dept of Family/Preventive Medicine
E mailto:[EMAIL PROTECTED] UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.