Question

I am trying to do sequence analysis using time-diary data (American Time Use Survey) using TraMineR in R. I have the data as SPELL data (id, start time, stop time, event) but I receive the following error when trying to convert it to STS or SPS data:

Error in as.matrix.data.frame(subset(data, , 2)) : dims [product 0] do not match the length of object [9]

I believe it has something to do with how I convert my time (as character) to date/time types. I believe TraMineR requires an POSIXlt format?

Here is a snippet of my raw data (trcode is the event)

head(atus.act.short)

     tucaseid tustarttim tustoptime trcode
1 2.00701e+13   04:00:00   08:00:00  10101
2 2.00701e+13   08:00:00   08:20:00 110101
3 2.00701e+13   08:20:00   08:50:00  10201
4 2.00701e+13   08:50:00   09:30:00  20102
5 2.00701e+13   09:30:00   09:40:00 180201
6 2.00701e+13   09:40:00   11:40:00  20102

I use strptime to convert the character strings to POSIXlt:

atus.act.short$starttime.new <- strptime(atus.act.short$tustarttim, format="%X")
atus.act.short$stoptime.new  <- strptime(atus.act.short$tustoptime, format="%X")

I also cut the ID down to only two digits

  atus.act.short$id <- atus.act.short$tucaseid-20070101070000

I end up with a new data frame as follows:

   id       starttime.new        stoptime.new trcode
1  44 2012-08-03 04:00:00 2012-08-03 08:00:00  10101
2  44 2012-08-03 08:00:00 2012-08-03 08:20:00 110101
3  44 2012-08-03 08:20:00 2012-08-03 08:50:00  10201
4  44 2012-08-03 08:50:00 2012-08-03 09:30:00  20102
5  44 2012-08-03 09:30:00 2012-08-03 09:40:00 180201
6  44 2012-08-03 09:40:00 2012-08-03 11:40:00  20102
7  44 2012-08-03 11:40:00 2012-08-03 11:50:00 180201
8  44 2012-08-03 11:50:00 2012-08-03 12:05:00  20102
9  44 2012-08-03 12:05:00 2012-08-03 13:05:00 120303
10 44 2012-08-03 13:05:00 2012-08-03 13:20:00 180704
11 44 2012-08-03 13:20:00 2012-08-03 15:20:00  70104
12 44 2012-08-03 15:20:00 2012-08-03 15:35:00 180704
13 44 2012-08-03 15:35:00 2012-08-03 17:00:00 120303
14 44 2012-08-03 17:00:00 2012-08-03 17:20:00 180701
15 44 2012-08-03 17:20:00 2012-08-03 17:25:00 180701
16 44 2012-08-03 17:25:00 2012-08-03 17:55:00  70101
17 44 2012-08-03 17:55:00 2012-08-03 18:00:00 181203
18 44 2012-08-03 18:00:00 2012-08-03 19:00:00 120303
19 44 2012-08-03 19:00:00 2012-08-03 19:30:00 110101
20 44 2012-08-03 19:30:00 2012-08-03 21:30:00 120303
21 44 2012-08-03 21:30:00 2012-08-03 23:00:00  10101
22 44 2012-08-03 23:00:00 2012-08-03 23:03:00  10201
26 48 2012-08-03 06:45:00 2012-08-03 08:15:00  10201
27 48 2012-08-03 08:15:00 2012-08-03 08:45:00 180209
28 48 2012-08-03 08:45:00 2012-08-03 09:00:00  20902
29 48 2012-08-03 09:00:00 2012-08-03 11:00:00  50101
30 48 2012-08-03 11:00:00 2012-08-03 11:45:00 120312

Then I try to create a sequence object [using library(TraMineR)]

atus.seq <- seqdef(atus.act.short, informat = "SPELL", id="id")

And I get the following error:

Error in as.matrix.data.frame(subset(data, , 2)) : dims [product 0] do not match the length of object [9]

Thoughts?

Answer 1

I’ve managed to work around this by converting the time to minutes (following another questions on stackoverflow), making the status code a character (as.character), using seqformat, and assigning it to a time axis. The new code reads:

atus.seq2 <- seqformat(atus.act.short2, id="id", from="SPELL", to="STS", begin = "startmin", end = "stopmin", status="trcode", process = "FALSE")