[R] Possible bug in 'data.table'
Manta
mantino84 at libero.it
Tue May 14 12:32:04 CEST 2013
Dear R users,
I may have found a bug in the function 'data.table'. I have a similar
question as the one in this post:
http://stackoverflow.com/questions/3367190/aggregate-and-weighted-mean-in-r
I have a dataset with assets, quantity traded, date and time. I would like
to calculate the value weighted average time of trades, by date of trade.
The variables are as follows:
Classes ‘data.table’ and 'data.frame': 307787 obs. of 12 variables:
$ CODE : int 1 2 3 4 4 5 3 2 2 1
$ DATE : int 20070102 20070102 20070102 20070102 20070102 20070102
20070102 20070102 20070102 20070102 ...
$ TIME : chr "09:14:14" "09:14:33" "09:26:19" "09:40:45" ...
$ PRICE : num 105.2 105.2 96.8 96.9 96.8 ...
$ QTY : int 5000000 5000000 5000000 10000000 5000000 5000000 10000000
3000000 10000000 5000000 ...
$ DATE2 : Date, format: "2007-01-02" "2007-01-02" "2007-01-02"
"2007-01-02" ...
$ TIME2 : chr "09:14:14" "09:14:33" "09:26:19" "09:40:45" ...
$ TIME3 : POSIXlt, format: "2013-05-13 09:14:14" "2013-05-13 09:14:33"
"2013-05-13 09:26:19" "2013-05-13 09:40:45" ...
- attr(*, ".internal.selfref")=<externalptr>
If I run the command
temp[,list(weighted.mean(PRICE,QTY)),by=DATE2]
I get
DATE2 V1
1: 2007-01-02 100.67024
2: 2007-01-03 99.89599
3: 2007-01-04 100.54347
4: 2007-01-05 100.82472
5: 2007-01-08 99.39865
---
1524: 2012-12-19 103.73392
1525: 2012-12-20 103.77344
1526: 2012-12-21 102.89063
1527: 2012-12-27 101.53089
1528: 2012-12-28 103.35999
While I run the command
temp[,list(weighted.mean(TIME3,QTY)),by=DATE2]
R crashes. This behavior occurs in both R Studio and R GUI, regardless of
the version (2.14, 2.15, 3.0). Is it really a bug or am I doing something
wrong?
--
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