title: Getting error "In function ‘igraph_write_graph_graphml’:" while installing igraph package in R
body: <p>I am trying to install igraph package in R.But getting error in the foreign-graphml.c below:</p>
  
  <pre><code>foreign-graphml.c: In function ‘igraph_write_graph_graphml’:
  foreign-graphml.c:1408:46: error: expected ‘)’ before ‘GRAPHML_NAMESPACE_URI’
     ret=fprintf(outstream, "&lt;graphml xmlns=\"" GRAPHML_NAMESPACE_URI "\"\n");
                                                ^
  foreign-graphml.c:1412:59: error: expected ‘)’ before ‘GRAPHML_NAMESPACE_URI’
     ret=fprintf(outstream, "         xsi:schemaLocation=\"" GRAPHML_NAMESPACE_URI
                                                             ^
  foreign-graphml.c:1414:38: error: expected ‘)’ before ‘GRAPHML_NAMESPACE_URI’
     ret=fprintf(outstream, "         " GRAPHML_NAMESPACE_URI "/1.0/graphml.xsd\"&gt;
                                        ^
  /usr/lib/R/etc/Makeconf:134: recipe for target 'foreign-graphml.o' failed
  make: *** [foreign-graphml.o] Error 1
  ERROR: compilation failed for package ‘igraph’
  * removing ‘/home/evangeline/R/x86_64-pc-linux-gnu-library/3.2/igraph’
  
  The downloaded source packages are in
      ‘/tmp/Rtmp9eBTml/downloaded_packages’
  Warning message:
  In install.packages("igraph") :
    installation of package ‘igraph’ had non-zero exit status  
  </code></pre>
  
  <p>Kindly help me out.</p>
  
  <p>Please find the sessionInfo:
  <strong>sessionInfo</strong>:</p>
  
  <pre><code>R version 3.2.3 (2015-12-10)
  Platform: x86_64-pc-linux-gnu (64-bit)
  Running under: Ubuntu 16.04.2 LTS
  
  locale:
   [1] LC_CTYPE=en_IN       LC_NUMERIC=C         LC_TIME=en_IN       
   [4] LC_COLLATE=en_IN     LC_MONETARY=en_IN    LC_MESSAGES=en_IN   
   [7] LC_PAPER=en_IN       LC_NAME=C            LC_ADDRESS=C        
  [10] LC_TELEPHONE=C       LC_MEASUREMENT=en_IN LC_IDENTIFICATION=C 
  
  attached base packages:
  [1] stats     graphics  grDevices utils     datasets  methods   base
  </code></pre>