<html><head><style>body{font-family:Helvetica,Arial;font-size:13px}</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">Hello,</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">Yes this seems to be a bug introduced sometime towards the end of the development cycle towards 1.9.x. Thanks for reporting. Will try to fix asap.</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">The problem is that `by=` doesn't retain the class. If you do: `dt[, print(d), by=list(id, d)]` you'll see that. For now, I guess you'll have to explicitly convert it back to POSIX/Date class and do your operations in `j`, until a commit with the fix is rolled out.</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div> <div id="bloop_sign_1395660060212428032" class="bloop_sign"><div style="font-family:helvetica,arial;font-size:13px">Arun</div></div> <div style="color:black"><br>From: <span style="color:black">dnlbrky</span> <a href="mailto:danielrlabar@gmail.com">danielrlabar@gmail.com</a><br>Reply: <span style="color:black">dnlbrky</span> <a href="mailto:danielrlabar@gmail.com">danielrlabar@gmail.com</a><br>Date: <span style="color:black">March 24, 2014 at 6:36:41 AM</span><br>To: <span style="color:black">datatable-help@lists.r-forge.r-project.org</span> <a href="mailto:datatable-help@lists.r-forge.r-project.org">datatable-help@lists.r-forge.r-project.org</a><br>Subject: <span style="color:black"> [datatable-help] "Error in Ops.POSIXt" using 1.9.x <br></span></div><br> <blockquote type="cite" class="clean_bq"><span><div><div></div><div>Running the following using data.table version 1.8.10 or 1.8.11 (Windows 7)
<br>works as expected:
<br>
<br>n <- 12
<br>dt <- data.table(id=rep(letters[1:(n/3)], each=3),
<br> d=seq(as.POSIXct("2013-01-01"), by="month", length.out=n))
<br>dt[, list(d2=seq(d, dt[, max(d)], by="month")), by=list(id, d)][1:15]
<br>
<br>> id d d2
<br>> 1: a 2013-01-01 2013-01-01
<br>> 2: a 2013-01-01 2013-02-01
<br>> 3: a 2013-01-01 2013-03-01
<br>> 4: a 2013-01-01 2013-04-01
<br>> 5: a 2013-01-01 2013-05-01
<br>> 6: a 2013-01-01 2013-06-01
<br>> 7: a 2013-01-01 2013-07-01
<br>> 8: a 2013-01-01 2013-08-01
<br>> 9: a 2013-01-01 2013-09-01
<br>> 10: a 2013-01-01 2013-10-01
<br>> 11: a 2013-01-01 2013-11-01
<br>> 12: a 2013-01-01 2013-12-01
<br>> 13: a 2013-02-01 2013-02-01
<br>> 14: a 2013-02-01 2013-03-01
<br>> 15: a 2013-02-01 2013-04-01
<br>
<br>After upgrading to 1.9.x (latest version at writing was 1.9.3) however, I
<br>get the following:
<br>
<br>>Error in Ops.POSIXt(del, by) : '/' not defined for "POSIXt" objects
<br>
<br>If I replace `seq` with `seq.Date` then I get:
<br>
<br>>Error in seq.Date(d, dt[, max(d)], by = "month") :
<br> 'from' must be a "Date" object
<br>
<br>Am I doing something wrong? Is this a bug? Is there a workaround?
<br>
<br>
<br>
<br>--
<br>View this message in context: http://r.789695.n4.nabble.com/Error-in-Ops-POSIXt-using-1-9-x-tp4687400.html
<br>Sent from the datatable-help mailing list archive at Nabble.com.
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