<div dir="ltr"><span style="font-family:arial,sans-serif;font-size:13px">Hello Steve and thanks for your reply. I am running data.table_1.8.11</span><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">
Full details below:<div><br></div><div><div>> sessionInfo()</div><div>R version 3.0.2 (2013-09-25)</div><div>Platform: x86_64-w64-mingw32/x64 (64-bit)</div><div><br></div><div>locale:</div><div>[1] LC_COLLATE=English_United Kingdom.1252 LC_CTYPE=English_United Kingdom.1252 </div>
<div>[3] LC_MONETARY=English_United Kingdom.1252 LC_NUMERIC=C </div><div>[5] LC_TIME=English_United Kingdom.1252 </div><div><br></div><div>attached base packages:</div><div>[1] stats graphics grDevices utils datasets methods base </div>
<div><br></div><div>other attached packages:</div><div> [1] timeDate_3010.98 data.table_1.8.11 quantstrat_0.7.8 </div><div> [4] foreach_1.4.1 blotter_0.8.15 PerformanceAnalytics_1.1.1</div>
<div> [7] FinancialInstrument_1.1 quantmod_0.4-0 Defaults_1.1-1 </div><div>[10] TTR_0.22-0 xts_0.9-5 zoo_1.7-10 </div><div><br></div><div>loaded via a namespace (and not attached):</div>
<div>[1] codetools_0.2-8 grid_3.0.2 iterators_1.0.6 lattice_0.20-23 plyr_1.8 </div><div>[6] reshape2_1.2.2 stringr_0.6.2 tools_3.0.2 </div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">
On Fri, Nov 22, 2013 at 2:45 PM, Steve Lianoglou <span dir="ltr"><<a href="mailto:lianoglou.steve@gene.com" target="_blank">lianoglou.steve@gene.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi Daniel,<br>
<div class="im"><br>
On Fri, Nov 22, 2013 at 6:15 AM, daniel.krizian<br>
<<a href="mailto:daniel.krizian@gmail.com">daniel.krizian@gmail.com</a>> wrote:<br>
> Hello, I have:<br>
><br>
> DT <- data.table(a=1:10, b=1:10,c=1:10, key=c("a","b"))<br>
> key(DT) # [1] "a" "b"<br>
> key(DT[,list(a,b)]) # NULL<br>
><br>
> Note that DT loses its key when I select a subset of columns like above.<br>
><br>
> Is this a (known) bug/ expected result?<br>
<br>
</div>The key is retained for me when I run your code:<br>
<br>
R> key(DT[,list(a,b)])<br>
[1] "a" "b"<br>
<br>
What version of data.table are you using?<br>
<span class="HOEnZb"><font color="#888888"><br>
-steve<br>
<br>
--<br>
Steve Lianoglou<br>
Computational Biologist<br>
Genentech<br>
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