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<div class="moz-cite-prefix"><br>
Hi Mel,<br>
<br>
Thanks for the info. It's likely related to cedta() and we can
handle it from data.table's side as follows.<br>
<br>
Background :<br>
<br>
<a class="moz-txt-link-freetext" href="http://stackoverflow.com/a/10529888/403310">http://stackoverflow.com/a/10529888/403310</a><br>
<br>
Type "data.table:::cedta" so you can see the rules. I guess
FastWeb is running your code in its own environment. First
thing, turn on verbosity :<br>
<br>
options(data.table.verbose=TRUE) # or for one statement
rather than globally, d1[d2,verbose=TRUE]<br>
<br>
and run your code again. You should see a message "cedta decided
'<nsname>' wasn't data.table aware", where <nsname>
is probably "FastRWeb".<br>
<br>
This calling environment (let's assume "FastRWeb" from now on) is
more like .GlobalEnv than a package; i.e., it's where you run
your own code, you've done library(data.table) in that
environment, and so it is data.table aware as far as you're
concerned. So what to do? There are two override mechanisms :<br>
<br>
The data.table package contains a character vector :<br>
<br>
> data.table:::cedta.override<br>
[1] "gWidgetsWWW"<br>
<br>
It already contains one package which is similar in nature. You
can add FastRWeb to that vector yourself as follows :<br>
<br>
> assignInNamespace("cedta.override",
c("gWidgetsWWW","FastRWeb"), "data.table")<br>
> data.table:::cedta.override<br>
[1] "gWidgetsWWW" "FastRWeb" <br>
<br>
But I'll also add FastRWeb to that vector in data.table, so from
the next version of data.table you won't have to do it yourself.
We'll add new packages as we become aware of them.<br>
<br>
Alternatively, the package author (Simon in this case) can
provide data.table-awareness optionally. This mechanism was added
for dplyr so it can control data.table awareness from the caller's
end. That's done by setting a variable
.datatable.aware=TRUE|FALSE in the calling package's namespace.
However, in the case of FastRWeb, the cedta.override on
data.table's side seems the right way to go.<br>
<br>
Matt<br>
<br>
<br>
On 18/02/14 05:31, Bacou, Melanie wrote:<br>
</div>
<blockquote cite="mid:5302F047.6020404@mbacou.com" type="cite">
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Hi Arun,<br>
<br>
This is a little tricky to reproduce unless you have installed
FastRWeb, and then started the FastRWeb server. I'm executing
these scripts from the browser through a call to FastRWeb running
on a local port.<br>
<br>
Installation is documented here and is quick and straightforward
on Linux:<br>
<a moz-do-not-send="true" href="https://rforge.net/FastRWeb/">https://rforge.net/FastRWeb/</a><br>
and an example here:<br>
<a moz-do-not-send="true"
href="http://jayemerson.blogspot.mx/2011/10/setting-up-fastrwebrserve-on-ubuntu.html">http://jayemerson.blogspot.mx/2011/10/setting-up-fastrwebrserve-on-ubuntu.html</a><br>
<br>
I'm using FastRWeb to build a simple web service. As long as I
stick to data.frame methods, everything works fine and I get the
expected plots and HTML output in the browser. But calls to
data.table methods (merge, extract) all seem to default to
data.frame, and I really don't know how to debug that.<br>
<br>
I am copying Simon Urbanek who's the maintainer of FastRWeb, in
case this is more of a FastRWeb issue.<br>
<br>
Here is my session info (I am on CentOS 5 and cannot easily
upgrade to R 3.0.2).<br>
<br>
> sessionInfo()<br>
R version 2.15.2 (2012-10-26)<br>
Platform: x86_64-redhat-linux-gnu (64-bit)<br>
<br>
locale:<br>
[1] C<br>
<br>
attached base packages:<br>
[1] stats graphics utils datasets grDevices methods
base <br>
<br>
other attached packages:<br>
[1] ggmap_2.3 ggplot2_0.9.3.1 RColorBrewer_1.0-5
raster_2.2-12 <br>
[5] rgeos_0.3-3 rgdal_0.8-16 sp_1.0-14
data.table_1.8.10 <br>
[9] RJDBC_0.2-3 rJava_0.9-6 DBI_0.2-7
rj_1.1.2-3 <br>
<br>
loaded via a namespace (and not attached):<br>
[1] MASS_7.3-23 RJSONIO_1.0-3 RgoogleMaps_1.2.0.5<br>
[4] colorspace_1.2-4 dichromat_2.0-0 digest_0.6.4 <br>
[7] grid_2.15.2 gtable_0.1.2 labeling_0.2 <br>
[10] lattice_0.20-24 mapproj_1.2-2 maps_2.3-6 <br>
[13] munsell_0.4.2 plyr_1.8 png_0.1-7 <br>
[16] proto_0.3-10 reshape2_1.2.2 rj.gd_1.1.0-1 <br>
[19] rjson_0.2.13 scales_0.2.3 stringr_0.6.2 <br>
[22] tools_2.15.2 <br>
<br>
Thanks all!<br>
--Mel.<br>
<br>
<br>
<br>
<br>
<div class="moz-cite-prefix">On 2/17/2014 6:58 AM, Arunkumar
Srinivasan wrote:<br>
</div>
<blockquote
cite="mid:CAAf756O7Z+_J5Zrmcu3dpNVU6CKaS82Vitd-pPYB1iwUKMDhfA@mail.gmail.com"
type="cite">
<div dir="ltr">Mel,
<div>I'm not able to reproduce this on 1.8.11. Which version
are you using?</div>
<div>I'm not aware of this package, and what 'otable' is
supposed to do. But I get no output while running your
script, and not the error message as well.</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Mon, Feb 17, 2014 at 11:14 AM,
Bacou, Melanie <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:mel@mbacou.com"
target="_blank">mel@mbacou.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> Hi,<br>
<br>
I am testing an R script using FastRWeb (through
Rserve). FastRWeb works as expected and I can
successfully runs Simon Urbanek's examples. Problems
arise when I try to merge datatables. It seems FastRWeb
cannot find <tt>merge.data.table()</tt>.<br>
<br>
I'm using plenty of other libraries (ggplot, raster,
RJDBC, etc.) that execute successfully through FastRWeb
scripts, so I'm guessing it's something peculiar to
data.table.<br>
<br>
Thanks for any help! --Mel.<br>
<br>
<br>
Here are reproducible examples.<br>
<br>
Test #1: the code below (the entire content of my R
script) SUCCEEDS:<br>
<br>
<tt># test1.R</tt><tt><br>
</tt><tt>library(data.table)</tt><tt><br>
</tt><tt><br>
</tt><tt>run <- function(...) {</tt><tt><br>
oclear()<br>
</tt><tt> d1 <- data.table(a=c(1,2,3),
b=c("a","b","c"))</tt><tt><br>
</tt><tt> d2 <- data.table(e=c("v","a","b"),
f=c(4,6,7))</tt><tt><br>
</tt><tt> otable(d1)</tt><tt><br>
</tt><tt> otable(d2)</tt><tt><br>
</tt><tt>}</tt><br>
<br>
This returns a simple web page showing 2 tables:<br>
<table style="font-family:'Times New
Roman';letter-spacing:normal;text-indent:0px;text-transform:none;word-spacing:0px">
<tbody>
<tr>
<td>1</td>
<td>a</td>
</tr>
<tr>
<td>2</td>
<td>b</td>
</tr>
<tr>
<td>3</td>
<td>c</td>
</tr>
</tbody>
</table>
<table style="font-family:'Times New
Roman';letter-spacing:normal;text-indent:0px;text-transform:none;word-spacing:0px">
<tbody>
<tr>
<td>v</td>
<td>4</td>
</tr>
<tr>
<td>a</td>
<td>6</td>
</tr>
<tr>
<td>b</td>
<td>7</td>
</tr>
</tbody>
</table>
<br>
<br>
Test #2: the code below (the entire content of my R
script) FAILS with:<tt><span><br>
<tt>Error in `[.default`(x, i) : invalid subscript
type 'list'</tt></span></tt><br>
<br>
<tt># test2.R<br>
</tt><tt> library(data.table)</tt><tt><br>
</tt><tt> </tt><tt><br>
</tt><tt> run <- function(...) {</tt><tt><br>
oclear()<br>
</tt><tt> d1 <- data.table(a=c(1,2,3),
b=c("a","b","c"))</tt><tt><br>
</tt><tt> d2 <- data.table(e=c("v","a","b"),
f=c(4,6,7))</tt><tt><br>
</tt><tt> otable(d1)</tt><tt><br>
</tt><tt> otable(d2)</tt><tt><br>
</tt><tt> setkey(d1, b)</tt><tt><br>
</tt><tt> setkey(d2, e)</tt><tt><br>
</tt><tt> otable(d1[d2])</tt><tt><br>
</tt><tt> }</tt><span class="HOEnZb"><font
color="#888888"><br>
<br>
<br>
<br>
<br>
<pre cols="72">--
Melanie BACOU
International Food Policy Research Institute
Agricultural Economist, HarvestChoice
Work <a moz-do-not-send="true" href="tel:%2B1%28202%29862-5699" value="+12028625699" target="_blank">+1(202)862-5699</a>
E-mail <a moz-do-not-send="true" href="mailto:mel@mbacou.com" target="_blank">mel@mbacou.com</a>
Visit <a moz-do-not-send="true" href="http://harvestchoice.org" target="_blank">harvestchoice.org</a> </pre>
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<pre class="moz-signature" cols="72">--
Melanie BACOU
International Food Policy Research Institute
Agricultural Economist, HarvestChoice
Work +1(202)862-5699
E-mail <a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:mel@mbacou.com">mel@mbacou.com</a>
Visit harvestchoice.org </pre>
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