[R] Questions about doing analysis based on time

John Kane jrkrideau at inbox.com
Fri Jun 22 21:18:27 CEST 2012 

Hi and welcome to the R-help list.

It would be much better for readers to get your data in a more easily used format.

There is a function called dput() that will output your data in a way that R can read easily.

We don't need to see all the data but perhaps hundred lines of it would be nice.  

Try this  where your file is called "mydata"
# just copy the line below and paste into R
head(mydata, 100) 

# Now copy the output and paste it into your wordprocess as a reply to the list and we will have decent data to work with.

John Kane
Kingston ON Canada


> -----Original Message-----
> From: mikeedinger16 at gmail.com
> Sent: Fri, 22 Jun 2012 09:21:40 -0700 (PDT)
> To: r-help at r-project.org
> Subject: [R] Questions about doing analysis based on time
> 
>
> I have a spreadsheet that I've read into R using read.csv.  I've also
> attached it.  It looks like this (except there are 1600+ entries):
> 
>> Sunday
>               SunDate SunTime SunScore
> 1       5/9/2010 0:00    0:00      127
> 2      6/12/2011 0:00    0:00      125
> 3      6/15/2008 0:04    0:04       98
> 4       8/3/2008 0:07    0:07      118
> 5      7/24/2011 0:07    0:07      122
> 6      5/25/2008 0:09    0:09      104
> 7      5/20/2012 0:11    0:11      124
> 8     10/18/2009 0:12    0:12      121
> 9      3/14/2010 0:12    0:12      117
> 10      1/2/2011 0:12    0:12      131
> 
> SunDate and SunTime are both factors.  In order to change the class to
> something I can work with, I use the following:
> 
> Sunday$SunTime<-as.POSIXlt(SunTime,tz=””,”%H:%M”)
> Sunday$SunDate<-as.POSIXlt(SunDate,tz=””,”%m/%d/%Y %H:%M”)
> 
> Now, the str(Sunday) command yields:
> 
> 'data.frame':   1644 obs. of  3 variables:
>  $ SunDate : POSIXlt, format: "2010-05-09 00:00:00" "2011-06-12 00:00:00"
> ...
>  $ SunTime : POSIXlt, format: "2012-06-18 00:00:00" "2012-06-18 00:00:00"
> ...
>  $ SunScore: int  127 125 98 118 122 104 124 121 117 131 ...
> 
> I think all the elements in Sunday are correct for me to do what I want
> to
> do, but I don't know how to do them.
> 
> 1. How can I get the mean score by hour?  For example, I want the mean
> score


> of all the entries between 0:00 and 0:59, then 1:00  and 1:59, etc.
> 2. Is it possible for me to create a histogram by hour for each score
> over a
> certain point?  For example, I want to make a histogram of all scores
> above
> 140 by the hour they occurred in.  Is that possible?
> 
> These last few might not be possibe (at least with R), but I'll ask
> anyway.
> I've got another data set similar to the one above, except it's got
> 12,000
> entries over four years.  If I do the same commands as above to turn Date
> and Time into POSIXlt, is it possible for me to do the following:
> 
> 1. The data was recorded at irregular intervals, and the difference
> between
> recorded points can range from anywhere between 1 hour and up to 7.  Is
> it
> possible, when data isn't recorded between two points, to insert the
> hours
> that are unrecorded along with the average of what that hour is.  This is
> sort of a pre-requisite for the next two.
> 2. If one of the entries has a Score above a certain point, is it
> possible
> to determine how long it was above that point and determine the mean for
> all
> the instances this occurred.  For example:
> 01/01/11 01:00 AM
> 101
> 01/01/11 02:21 AM
> 142
> 01/01/11 03:36 AM
> 156
> 01/01/11 04:19 AM
> 130
> 01/01/11 05:12 AM
> 146
> 01/01/11 06:49 AM
> 116
> 01/01/11 07:09 AM
> 111
> 	There are two spans where it's above 140. The two and three o'clock
> hours,
> and the 5 o'clock hour.  So the mean time would be 1.5 hours.  Is it
> possible for R to do this over a much larger time period?
> 
> 3.  If a score reaches a certain point, is it possible for R to determine
> the average time between that and when the score reaches another point.
> For
> example:
> 01/01/11 01:01 AM
> 101
> 01/01/11 02:21 AM
> 121
> 01/01/11 03:14 AM
> 134
> 01/01/11 04:11 AM
> 149
> 01/01/11 05:05 AM
> 119
> 01/01/11 06:14 AM
> 121
> 01/01/11 07:19 AM
> 127
> 01/01/11 08:45 AM
> 134
> 01/01/11 09:11 AM
> 142
> 01/01/11 10:10 AM
> 131
> The score goes above 120 during the 2 AM hour and doesn't go above 140
> until
> the 4 AM hour.  Then it goes above 120 again in the 6 AM hour, but
> doesn't
> go above 140 until the 9 AM hour.  So the average time to go from 120 to
> 140
> is 2.5 hours.  Can R does this over a much larger time frame?
> 
> If anyone knows how to easily do any of these (particularly the first
> part),
> I'd greatly appreciate it.
> 
> If some of these are possible, but aren't simple commands and require
> more
> in depth programming knowledge and time commitment, can someone at least
> tell me what sort of thing to look up?
> 
> --
> View this message in context:
> http://r.789695.n4.nabble.com/Questions-about-doing-analysis-based-on-time-tp4634230.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
.

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