[R] How to format data for time-series analysis

[jim holtman]

Just add the steps to do the conversion yourself.  Also you data seems
to be missing columns, at least in the mail you sent.  Also the 'zoo'
object will be a character matrix.

> x <- read.table(tc <- textConnection("       Time Event State Value
+ 24-10-20   BMU          20
+ 25-10-20 Image           2
+ 26-10-20   BMU          10
+ 27-10-20   BMU          11
+ 28-10-20 Image           3
+ 29-10-20  DPMS Begin    NA
+ 30-10-20 Dream Begin    NA
+ 31-10-20   BMU           3
+  1-11-20 Image           4
+  2-11-20   BMU          50
+  3-11-20   BMU          20
+  4-11-20  DPMS   End    NA
+  5-11-20 Dream   End    NA
+ "), fill=TRUE, header=TRUE)
> close(tc)
> # convert the times
> x$Time <- as.Date(as.character(x$Time), "%d-%m-%y")
> # convert to zoo
> require(zoo)
> x.z <- zoo(x[-1], x[[1]])
> str(x.z)
 chr [1:13, 1:3] "BMU" "Image" "BMU" "BMU" "Image" "DPMS" "Dream"
"BMU" "Image" ...
 - attr(*, "dimnames")=List of 2
  ..$ : chr [1:13] "1" "2" "3" "4" ...
  ..$ : chr [1:3] "Event" "State" "Value"
 - attr(*, "index")=Class 'Date'  num [1:13] 18559 18560 18561 18562 18563 ...
> x.z
           Event State Value
2020-10-24 BMU   20    <NA>
2020-10-25 Image 2     <NA>
2020-10-26 BMU   10    <NA>
2020-10-27 BMU   11    <NA>
2020-10-28 Image 3     <NA>
2020-10-29 DPMS  Begin <NA>
2020-10-30 Dream Begin <NA>
2020-10-31 BMU   3     <NA>
2020-11-01 Image 4     <NA>
2020-11-02 BMU   50    <NA>
2020-11-03 BMU   20    <NA>
2020-11-04 DPMS  End   <NA>
2020-11-05 Dream End   <NA>
>


On 10/28/07, B. Bogart <bbogart at sfu.ca> wrote:
> Hey all again,
>
> So I'm going through tutorials and getting a better sense of R structures.
>
> So I made some mockup data to see if I can figure out how to load it
> properly. (attached) if anyone has any suggestions on a better way to
> structure that data please let me know.
>
> So the file has three columns, the date/time of the event, the event
> name, the event state (if there is one) and the event value (if there is
> one). I'm using the built-in date/time class of openoffice as a starting
> point for the date/time.
>
> I'm expecting to load this file as a data.frame where each column is a
> different class. Like so:
>
>  > data <-
> read.table(file="testdata.csv",sep=",",header=TRUE,colClasses=c("zoo","factor","factor","numeric"))
>
> Unfortunately It seems there is no function for converting from
> "character" to "zoo":
>
> Error in methods::as(data[[i]], colClasses[i]) :
>         no method or default for coercing "character" to "zoo"
>
> So I tried using POSIXct as suggested.
>
> Which does load the file, but it seems the times are truncated, leaving
> only the dates:
>
>  > data
>        Time Event State Value
> 1  24-10-20   BMU          20
> 2  25-10-20 Image           2
> ...3  26-10-20   BMU          10
> 4  27-10-20   BMU          11
> 5  28-10-20 Image           3
> 6  29-10-20  DPMS Begin    NA
> 7  30-10-20 Dream Begin    NA
> 8  31-10-20   BMU           3
> 9   1-11-20 Image           4
> 10  2-11-20   BMU          50
> 11  3-11-20   BMU          20
> 12  4-11-20  DPMS   End    NA
> 13  5-11-20 Dream   End    NA
>
> Same results as using "Date" as the colClass.
>
> Any advice?
>
> Thanks,
> B. Bogart
>
>
>
>
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> and provide commented, minimal, self-contained, reproducible code.
>
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?