Error(s) in re-building vignettes:
--- re-building ‘ilc.Rnw’ using Sweave
Error: processing vignette 'ilc.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'ilc.tex' failed.
LaTeX errors:
! Undefined control sequence.
<argument> \z 
              
l.71 \begin{abstract}
                     
! Missing number, treated as zero.
<to be read again> 
                   @
l.71 \begin{abstract}
                     
! Illegal unit of measure (pt inserted).
<to be read again> 
                   @
l.71 \begin{abstract}
                     
! Package calc Error: `@' invalid at this point.

See the calc package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
! Extra }, or forgotten \endgroup.
\@vspace ... \@vspace@calcify {#1}\vskip \z@skip }
                                                  \@esphack \fi 
l.71 \begin{abstract}
                     
! Extra }, or forgotten \endgroup.
<recently read> }
                 
l.71 \begin{abstract}
                     
! Undefined control sequence.
<argument> \z 
              
l.71 \begin{abstract}
                     
! Missing number, treated as zero.
<to be read again> 
                   @
l.71 \begin{abstract}
                     
! Illegal unit of measure (pt inserted).
<to be read again> 
                   @
l.71 \begin{abstract}
                     
! Package calc Error: `@' invalid at this point.

See the calc package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
! Extra }, or forgotten \endgroup.
\@vspace ... \@vspace@calcify {#1}\vskip \z@skip }
                                                  \@esphack \fi 
l.71 \begin{abstract}
                     
! Extra }, or forgotten \endgroup.
<recently read> }
                 
l.71 \begin{abstract}
                     
! Missing } inserted.
<inserted text> 
                }
l.71 \begin{abstract}
                     
! Missing } inserted.
<inserted text> 
                }
l.71 \begin{abstract}
                     
! Missing } inserted.
<inserted text> 
                }
l.71 \begin{abstract}
                     
! LaTeX Error: Something's wrong--perhaps a missing \item.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
! LaTeX Error: \begin{center} on input line 71 ended by \end{abstract}.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
! Missing } inserted.
<inserted text> 
                }
l.78  \end{abstract}
                    
! LaTeX Error: \begin{center} on input line 71 ended by \end{document}.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
--- failed re-building ‘ilc.Rnw’

SUMMARY: processing the following file failed:
  ‘ilc.Rnw’

Error: Vignette re-building failed.
Execution halted