Merge lp:~mvngu/igraph/doc into lp:~igraph/igraph/0.6-main-old

[Minh Van Nguyen]

Here is a description of the first patch. With trunk #2646, building the HTML version of the documentation resulted in the following error:

if [ "x.." != "x.." ]; then cp ../doc/fdl.xml ../doc/gpl.xml ../doc/installation.xml ../doc/introduction.xml ../doc/tutorial.xml ../doc/licenses.xml ../doc/pmt.xml . ; fi && \
 xmlto -x ../doc/gtk-doc.xsl -o html xhtml igraph-docs.xml \
 && touch html/stamp
xmlto: /home/mvngu/apps/igraph-hg/doc/igraph-docs.xml does not validate (status 3)
xmlto: Fix document syntax or use --skip-validation option
structural.xml:6982: element para: validity error : Element em is not declared in para list of possible children
structural.xml:6982: element para: validity error : Element em is not declared in para list of possible children
structural.xml:6983: element em: validity error : No declaration for element em
structural.xml:6983: element em: validity error : No declaration for element em
Document /home/mvngu/apps/igraph-hg/doc/igraph-docs.xml does not validate
make: *** [html/stamp] Error 13

This is due to using the HTML tag <em></em> in the documentation of the function igraph_linegraph(). A fix is to use doxygen's syntax for emphasizing words, i.e. the tag \em in doxygen.

Here is a description of the second patch. In the function igraph_get_eid(), the documentation for the parameter error is misleading. The current documentation for error implies that if error is set to false and the required edge is not found, then the function will return -1. This is clearly not the behaviour of the function. If the boolean error is set to false and the required edge is not found, then the parameter eid will be assigned value -1. My second patch makes this change in documentation.

[Gábor Csárdi (gabor.csardi)]

All clean.

review: Approve

=== modified file 'src/structural_properties.c'
--- src/structural_properties.c	2012-02-16 16:23:54 +0000
+++ src/structural_properties.c	2012-03-05 02:31:18 +0000
@@ -4696,7 +4696,7 @@
  * is the same as the source of the second vertex's corresponding edge.
  * 
  * </para><para>
- * Edge <em>i</em> in the original graph will correspond to vertex <em>i</em>
+ * Edge \em i  in the original graph will correspond to vertex \em i
  * in the line graph.
  *
  * </para><para>

=== modified file 'src/type_indexededgelist.c'
--- src/type_indexededgelist.c	2011-10-19 17:07:45 +0000
+++ src/type_indexededgelist.c	2012-03-05 02:31:18 +0000
@@ -1112,7 +1112,7 @@
  * \param directed Logical constant, whether to search for directed
  *        edges in a directed graph. Ignored for undirected graphs.
  * \param error Logical scalar, whether to report an error if the edge 
- *        was not found. If it is false, then -1 is reported.
+ *        was not found. If it is false, then -1 will be assigned to \p eid.
  * \return Error code. 
  * \sa \ref igraph_edge() for the opposite operation.
  *