[R] Help with a problem

[Joshua Wiley]

Hi Michael,

The days in your example do not look continuous (at least from my
thinking), so you may have extra requirements in mind, but take a look
at this code.  My general thought was first to turn each column into a
logical vector (c1 >= 100 and c2 >= 8).  Taking advantage of the fact
that R treats TRUE as 1 and FALSE as 0, compute a rolling mean.  If
(and only if) 5 consecutive values are TRUE, the mean will be 1.  Next
I added the rolling means for each column, and then tested whether any
were 2 (i.e., 1 + 1).

Cheers,

Josh

###################
#Load required package
library(zoo)

#Your data with ds converted to Date
#from dput()
dat <-
structure(list(ds = structure(c(14702, 14729, 14730, 14731, 14732,
14733, 14734, 14735, 14736, 14737, 14738, 14739, 14740, 14741,
14742, 14743, 14744), class = "Date"), c1 = c(100L, 11141L, 3L,
7615L, 6910L, 5035L, 3007L, 4L, 8335L, 2897L, 6377L, 3177L, 7946L,
8705L, 9030L, 8682L, 8440L), c2 = c(0L, 15L, 16L, 14L, 17L, 3L,
15L, 14L, 17L, 13L, 17L, 17L, 15L, 0L, 16L, 16L, 1L)), .Names = c("ds",
"c1", "c2"), row.names = c(NA, -17L), class = "data.frame")

#Order by ds
dat <- dat[order(dat$ds), ]

yourvar <- 0

#Test that 5 consecutive values from c1 AND c2 meet requirements
if(any(
 c(rollmean(dat$c1 >= 100, 5) + rollmean(dat$c2 >= 8, 5)) == 2)
   ) {yourvar <- 1}

###################

On Sat, Jul 17, 2010 at 2:38 PM, Michael Hess <mlhess at med.umich.edu> wrote:
> Sorry for not being clear.
>
> In the dataset there are around 100 or so days of data (in the case also rows of data)
>
> I need to make sure that the person meets that c1 is at least 100 AND c2 is at least 8 for 5 of 7 continuous days.
>
> I will play with what I have and see if I can find out how to do this.
>
> Thanks for the help!
>
> Michael
>
>>>> Stephan Kolassa  07/17/10 4:50 PM >>>
> Mike,
>
> I am slightly unclear on what you want to do. Do you want to check rows
> 1 and 7 or 1 *to* 7? Should c1 be at least 100 for *any one* or *all*
> rows you are looking at, and same for c2?
>
> You can sort your data like this:
> data <- data[order(data$ds),]
>
> Type ?order for help. But also do this for added enlightenment...:
>
> library(fortunes)
> fortune("dog")
>
> Next, your analysis on the sorted data frame. As I said, I am not
> entirely clear on what you are looking at, but the following may solve
> your problem with choices "1 to 7" and "any one" above.
>
> foo <- 0
> for ( ii in 1:(nrow(data)-8) ) {
>   if (any(data$c1[ii+seq(0,6)]>=100) & any(data$c2[ii+seq(0,6)]>=8)) {
>     foo <- 1
>     break
>   }
> }
>
> The variable "foo" should contain what you want it to. Look at ?any
> (and, if this does not do what you want it to, at ?all) for further info.
>
> No doubt this could be vectorized, but I think the loop is clear enough.
>
> Good luck!
> Stephan
>
>
>
> Michael Hess schrieb:
>> Hello R users,
>>
>> I am a researcher at the University of Michigan looking for a solution to an R problem.  I have loaded my data in from a mysql database and it looks like this
>>
>>> data
>>            ds c1 c2
>> 1  2010-04-03        100           0
>> 2  2010-04-30      11141          15
>> 3  2010-05-01      3          16
>> 4  2010-05-02       7615          14
>> 5  2010-05-03       6910          17
>> 6  2010-05-04       5035          3
>> 7  2010-05-05       3007          15
>> 8  2010-05-06       4          14
>> 9  2010-05-07       8335          17
>> 10 2010-05-08       2897          13
>> 11 2010-05-09       6377          17
>> 12 2010-05-10       3177          17
>> 13 2010-05-11       7946          15
>> 14 2010-05-12       8705          0
>> 15 2010-05-13       9030          16
>> 16 2010-05-14       8682          16
>> 17 2010-05-15       8440          15
>>
>>
>> What I am trying to do is sort by ds, and take rows 1,7, see if c1 is at least 100 AND c2 is at least 8. If it is not, start with check rows 2,8 and if not there 3,9....until it loops over the entire file.   If it finds a set that matches, set a new variable equal to 1, if never finds a match, set it equal to 0.
>>
>> I have done this in stata but on this project we are trying to use R.  Is this something that can be done in R, if so, could someone point me in the correct direction.
>>
>> Thanks,
>>
>> Michael Hess
>> University of Michigan
>> Health System
>>
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>>
>
>
> **********************************************************
> Electronic Mail is not secure, may not be read every day, and should not be used for urgent or sensitive issues
>
> ______________________________________________
> 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.
>



-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/