[Traminer-users] Possible TraMineR bug: Displaying an event sequence object crashes R (reproducible)

[Bertolt Meyer]

Dear TraMineR developers,

I may have come across a bug in TraMineR: R (Version 2.14.2) crashes if I try to display my event sequence object. I tried it on different machines and the problem is reproducible. An executable code snipped reproducing the problem is at the bottom of the mail. 

I have a data set containing 45 sequences, min/max sequence length: 176/415. These are 45 group discussions, for which the discussants' speech acts have been coded as the states. Creating the sequence works fine:

> my_seq <- seqdef(my_seq_data_wide, 2:416, states = my_seq_data.alphabet, labels = my_seq_data.labels)
 [>] found missing values ('NA') in sequence data
 [>] preparing 45 sequences
 [>] coding void elements with '%' and missing values with '*'
 [>] alphabet (state labels): 
     1 = C (Content_Neither...nor)
     2 = CP (Content_Proposal)
     3 = CQ (Content_Question)
     4 = R (Regulation_Neither...nor)
     5 = RP (Regulation_Proposal)
     6 = RQ (Regulation_Question)
     7 = SEn (SENegative_Neither...nor)
     8 = SEnP (SENegative_Proposal)
     9 = SEnQ (SENegative_Question)
     10 = SEp (SEPositive_Neither...nor)
     11 = SEpP (SEPositive_Proposal)
     12 = SEpQ (SEPositive_Question)
 [>] 45 sequences in the data set
 [>] min/max sequence length: 176/415

Calculating transition rates with seqtrate() works well. However, executing the second line of the following two lines of code crashes R:

my_seqe <- seqecreate(my_seq)
my_seqe

I assume that there is something in the data that TraMineR cannot deal with, because it works if I limit the length of the sequences to 29, i.e., 

my_seq_short <- seqdef(my_seq_data_wide, 2:30, states = my_seq_data.alphabet, labels = my_seq_data.labels)

my_seqe <- seqecreate(my_seq_short)
my_seqe

Could this be a bug? Please find the complete code for reproducing this problem below.

Best greetings,
Bertolt

# Complete code for reproducing the problem:
# Load data set (takes a while, ~2 MB):
my_seq_data_long <- read.csv(file = "http://dl.dropbox.com/u/5384027/ex_data_bertolt.csv")
str(my_seq_data_long)

# Convert to wide format
my_seq_data_wide <- reshape(my_seq_data_long[,c("Group_number", "Number", "main_min_category")], 
                      idvar = "Group_number", timevar = "Number", direction = "wide")

names(my_seq_data_wide) # The sequence events span variables 2:416

# Create labels for sequence data
my_seq_data.labels <- levels(my_seq_data_long$main_min_category)
my_seq_data.labels

# Create alphabet
my_seq_data.alphabet <- c("C", "CP", "CQ", "R", "RP", "RQ", 
                    "SEn", "SEnP", "SEnQ", "SEp", "SEpP", "SEpQ")
my_seq_data.alphabet

# Create state sequence object
library(TraMineR)
my_seq <- seqdef(my_seq_data_wide, 2:416, states = my_seq_data.alphabet, labels = my_seq_data.labels)

# Calculate transition rates
round(seqtrate(my_seq), 2)

# Creating an event sequence object works if I use short sequences:
my_seq_short <- seqdef(my_seq_data_wide, 2:30, states = my_seq_data.alphabet, labels = my_seq_data.labels)
my_seqe <- seqecreate(my_seq_short)
my_seqe

# However, if I use the full data set, R crashes when calling the second line of 
# the following two lines:
my_seqe <- seqecreate(my_seq)
my_seqe


--
Dr. Bertolt Meyer, Dipl.-Psych.
Lehrstuhlvertretung 
Institut für Psychologie
Wirtschafts-, Organisations- und Sozialpsychologie

TU Chemnitz
Wilhelm-Raabe-Straße 43
09107 Chemnitz

Tel: +49 (0)371 531-32972
Fax: +49 (0)371 531-839627

mail: bertolt.meyer at psychologie.tu-chemnitz.de
web: http://www.tu-chemnitz.de/hsw/psychologie/professuren/sozpsy/meyer.php