<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:10.5pt;
font-family:Consolas;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:Consolas;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>All,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>My colleagues and I have been working hard to root out old code since 1.7.8 but every now and then for reasons I can’t discern I get errors like:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoPlainText>Error in `[.data.table`(x, , `:=`(i, .xi), with = FALSE) :<o:p></o:p></p><p class=MsoPlainText> At an earlier point, this data.table has been copied by R. Avoid key<-, names<- and attr<- which in R currently (and oddly) all copy the whole data.table. Use set* syntax instead to avoid copying:<o:p></o:p></p><p class=MsoPlainText>setkey(), setnames() and setattr(). If this message doesn't help, please ask on datatable-help.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>If I have data.table objects created with an earlier version of data.table, do they function exactly the same with the updated version of data.table. Or do they need to be re-data.tabled? <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Strangely, the above error disappeared when we did some cleaning on the data.set and resaved it?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Puzzled,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Damian Betebenner<span style='color:navy'><o:p></o:p></span></p><p class=MsoNormal>Center for Assessment<span style='color:navy'><o:p></o:p></span></p><p class=MsoNormal>PO Box 351<span style='color:navy'><o:p></o:p></span></p><p class=MsoNormal>Dover, NH 03821-0351<span style='color:navy'><o:p></o:p></span></p><p class=MsoNormal><span style='color:navy'> <o:p></o:p></span></p><p class=MsoNormal>Phone (office): (603) 516-7900<span style='color:navy'><o:p></o:p></span></p><p class=MsoNormal>Phone (cell): (857) 234-2474<span style='color:navy'><o:p></o:p></span></p><p class=MsoNormal>Fax: (603) 516-7910<span style='color:navy'><o:p></o:p></span></p><p class=MsoNormal><span style='color:navy'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:navy'><a href="mailto:dbetebenner@nciea.org"><span style='color:blue'>dbetebenner@nciea.org</span></a><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:navy'><a href="http://www.nciea.org/"><span style='color:blue'>www.nciea.org</span></a><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:navy'><o:p> </o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>