Doc: node and cell ordering in a structured mesh.

diff --git a/doc/user/doxygen/doxfiles/faq.dox b/doc/user/doxygen/doxfiles/faq.dox
index 1b81cb07960efc1c8158c5a77d18db7c80703a79..a01e6d16f9793e8626cc08c89bcadfc51b038550 100644 (file)
--- a/doc/user/doxygen/doxfiles/faq.dox
+++ b/doc/user/doxygen/doxfiles/faq.dox
@@ -14,6 +14,7 @@ Python API is almost 100% identical to the C++ one, with the \ref python-api "ru
     -# \ref f-visu
     -# \ref f-p0p1
     -# \ref f-number
+    -# \ref f-struct-ordering
     
 \ref faq-python
     -# \ref f-hellow
@@ -35,25 +36,29 @@ Python API is almost 100% identical to the C++ one, with the \ref python-api "ru
 
 \section Answers
 \subsection faq-general General questions
-\subsubsection f-newbie "I am a complete newbie, where should I start?"
+\subsubsection f-newbie I am a complete newbie, where should I start?
 Take a look at the \ref start "getting started" section and the \ref tutorial.
 
-\subsubsection f-mehsf "What is a mesh, what is a field?"
+\subsubsection f-mehsf What is a mesh, what is a field?
 Take a look at \ref terminology
 
-\subsubsection f-constel "What is a the difference between MED file, MEDCoupling and the SALOME MED module?"
+\subsubsection f-constel What is a the difference between MED file, MEDCoupling and the SALOME MED module?
 Take a look at \ref library
 
-\subsubsection f-visu "How can I visualize a mesh and/or a field?"
+\subsubsection f-visu How can I visualize a mesh and/or a field?
 Use the PARAVIS module of SALOME to visualize your MED file. The following dedicated fitlers have been 
 written specifically for MED files: Extract group, Extract cell types, ELNO Mesh, ELNO Points, ELNO Surface.
 
-\subsubsection f-p0p1 "What does a P0- (or P1-) field mean?"
+\subsubsection f-p0p1 What does a P0- (or P1-) field mean?
 Take a look at \ref terminology
 
-\subsubsection f-number "What does surjective/old-2-new/new-2-old format mean?"
+\subsubsection f-number What does surjective/old-2-new/new-2-old format mean?
 Take a look at \ref numbering
 
+\subsubsection f-struct-ordering What is the implicit numbering of a structured mesh?
+When converting a structured mesh to unstructured one, or when storing a field onto a structured
+mesh, the numbering convention detailed in \ref MEDCoupling::MEDCouplingStructuredMesh::buildUnstructured() is used.
+
 \subsection faq-python MEDCoupling scripts in Python 
 \subsubsection f-hellow "Can you show me a simple example to get me started"
 TODO

diff --git a/src/MEDCoupling/MEDCouplingStructuredMesh.cxx b/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
index aa83f7f1591ed91a6fe754afc9cd62c144cb5398..de85a9df721dee0ccec29d74ca31d550c850f2bb 100644 (file)
--- a/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
+++ b/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
@@ -338,6 +338,10 @@ void MEDCouplingStructuredMesh::splitProfilePerType(const DataArrayInt *profile,
 
 /*!
  * Creates a new unstructured mesh (MEDCoupling1SGTUMesh) from \a this structured one.
+ *
+ * In the returned mesh, the nodes are ordered with the first axis varying first: (X0,Y0), (X1,Y0),  ... (X0,Y1), (X1,Y1), ...
+ * and the cells are ordered with the same logic, i.e. in (i,j) notation: (0,0), (1,0), (2,0), ... (0,1), (1,1), ...
+ *
  *  \return MEDCouplingUMesh * - a new instance of MEDCouplingUMesh. The caller is to
  * delete this array using decrRef() as it is no more needed. 
  *  \throw If \a this->getMeshDimension() is not among [1,2,3].
@@ -381,6 +385,10 @@ MEDCoupling1SGTUMesh *MEDCouplingStructuredMesh::build1SGTSubLevelMesh() const
 
 /*!
  * Creates a new unstructured mesh (MEDCouplingUMesh) from \a this structured one.
+ *
+ * In the returned mesh, the nodes are ordered with the first axis varying first: (X0,Y0), (X1,Y0),  ... (X0,Y1), (X1,Y1), ...
+ * and the cells are ordered with the same logic, i.e. in (i,j) notation: (0,0), (1,0), (2,0), ... (0,1), (1,1), ...
+ *
  *  \return MEDCouplingUMesh * - a new instance of MEDCouplingUMesh. The caller is to
  * delete this array using decrRef() as it is no more needed. 
  *  \throw If \a this->getMeshDimension() is not among [1,2,3].