<html 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=utf-8"><meta name=Generator content="Microsoft Word 15 (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;}
/* 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:#954F72;
text-decoration:underline;}
.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></head><body lang=EN-US link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Dear list</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have written the following function to produce multidimensional arrays using Rcpp:</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-family:"Courier New"'>NumericVector arrayFromVector(NumericVector input, IntegerVector dim) { <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> // check for zero-length vectors<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> if(dim.length() == 0 || input.length() == 0) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> return NULL;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> long p = 1;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> for(int i = 0; i < dim.length(); i++) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> p *= dim[i];<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> if((input.length() == 1) & (p > 1)) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> input = Rcpp::rep_each(input, p);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> } else if (input.length() != p) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> return NULL;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> } <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> input.attr("dim") = dim;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'> return input;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New"'>}<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>This function usually produces the desired result, but in some cases (it seems with relatively large vector lengths) I get the error “negative length vectors are not allowed.” The error occurs on the line:</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> input = Rcpp::rep_each(input, p);</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I changed p from an int to a long, thinking I was encountering an overflow issue. But this did not resolve the problem. The test vector contains 45,000 values.</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Any suggestions?</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks in advance</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Barth</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986">Mail</a> for Windows 10</p><p class=MsoNormal><o:p> </o:p></p></div></body></html>