From: ageay Date: Tue, 12 Oct 2010 09:04:21 +0000 (+0000) Subject: Some docs. X-Git-Tag: V5_1_5~21 X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=91b8164269290c3006905e855e1804e3f8ffac04;p=tools%2Fmedcoupling.git Some docs. --- diff --git a/doc/doxygen/Doxyfile_med_user.in b/doc/doxygen/Doxyfile_med_user.in index fe0058878..98d26f422 100644 --- a/doc/doxygen/Doxyfile_med_user.in +++ b/doc/doxygen/Doxyfile_med_user.in @@ -96,6 +96,7 @@ FILE_PATTERNS = MEDMEM_Mesh.* \ PlanarIntersector.* \ TargetIntersector.* \ Interpolation.* \ + InterpolationOptions.* \ InterpKernelGeo2DAbstractEdge.* \ InterpKernelGeo2DEdge.* \ InterpKernelGeo2DEdgeArcCircle.* \ @@ -114,6 +115,8 @@ FILE_PATTERNS = MEDMEM_Mesh.* \ MEDCouplingFieldDouble.* \ MEDCouplingFieldDiscretization.* \ MEDCouplingTimeDiscretization.* \ + MEDCouplingMemArray.* \ + MEDCouplingRemapper.* \ MEDLoader.* \ *.dox RECURSIVE = NO diff --git a/doc/doxygen/interpkernel.dox b/doc/doxygen/interpkernel.dox index afe4b70c3..bfed9661f 100644 --- a/doc/doxygen/interpkernel.dox +++ b/doc/doxygen/interpkernel.dox @@ -214,10 +214,33 @@ interpolation. To be able to be filled by the interpolator the \c MatrixType cla \subsection InterpKerHighLevUsage high-level usage -This the simplest mode of usage of interpolator. This way is strongly -linked with MED data-structure. All interpolators is completely hidden -to you. Even sparse interpolation matrix is hidden. An exemple of -usage : +The simplest mode of usage of interpolator in sequential mode is to use REMAPPER classes. These classes fulfill HXX2SALOME rules to allow the user to use it +in coupling graphs. 2 REMAPPERS exist, ParaMEDMEM::MEDCouplingRemapper and Remapper. These classes are strongly linked to their corresponding data structure, respectively +MEDCoupling and MEDMEM. In return, all interpolation request and spare interpolation matrix are hidden from you. Here two examples of REMAPPER classes : + +- If you intend to use MEDCoupling data struture, ParaMEDMEM::MEDCouplingRemapper class should be used : + +\code +... +const char sourceFileName[]="source.med"; +MEDCouplingFieldDouble *sourceField=MEDLoader::ReadFieldCell(sourceFileName,"Source_Mesh",0,"Density",/*iteration*/0,/*order*/0); +const char targetFileName[]="target.med"; +MEDCouplingUMesh *med_target_mesh=MEDLoader::ReadUMeshFromFile(targetFileName,"Target_Mesh",0); +// +sourceField->setNature(ConservativeVolumic);//Specify nature is needed to allow remapper object to apply correct policy for denominator computation ! +MEDCouplingRemapper remapper; +remapper.setPrecision(1e-12); +remapper.setIntersectionType(INTERP_KERNEL::Triangulation); +remapper.prepare(sourceField->getMesh(),med_target_mesh,"P0P0"); +MEDCouplingFieldDouble *targetField=remapper.transferField(sourceField,/*default_value*/4.57);//Any target cell not intercepted by any source cell will have value set to 4.57. +... +// clean-up +targetField->decrRef(); +sourceField->decrRef(); +med_target_mesh->decrRef(); +\endcode + +- If you intend to use MEDMEM data structure, Remapper class should be used : \code ... @@ -244,7 +267,29 @@ As consequence of genericity of interpolators, they are usable only by instanciating an underneath mesh data structure. The two following examples show how to use interpolator at this level. -- The simplest way to use the interpolator with MED datastructure is : +- The simplest way to use interpolator with MEDCoupling datastruture is put in the following example. Note that this code is close to those used by ParaMEDMEM +to perform synchronization of meshes between processes of a MPI communicator : + +\code +... +MEDCouplingUMesh *med_source_mesh=MEDLoader::ReadUMeshFromFile("source.med","Source_mesh",0); +MEDCouplingUMesh *med_target_mesh=MEDLoader::ReadUMeshFromFile("target.med","Target_mesh",0); +MEDCouplingNormalizedUnstructuredMesh<2,2> wrap_source_mesh(med_source_mesh); +MEDCouplingNormalizedUnstructuredMesh<2,2> wrap_target_mesh(med_target_mesh); +// Go for interpolation... +INTERP_KERNEL::Interpolation2D myInterpolator; +myInterpolator.setPrecision(1e-7); +myInterpolator.setIntersectionType(INTERP_KERNEL::Geometric2D); +std::vector > resultMatrix; +INTERP_KERNEL::Matrix resultMatrix2; +// here the interpolation is performed twice for this code to show the capability of storing data of out matrix in 2 different data structures. +myInterpolator.interpolateMeshes(wrap_source_mesh,wrap_target_mesh,resultMatrix,"P0P0"); +myInterpolator.interpolateMeshes(wrap_source_mesh,wrap_target_mesh,resultMatrix2,"P0P0"); +//Ok resultMatrix and resultMatrix2 contain matrix now +... +\endcode + +- An another way to use the interpolator with MEDMEM datastructure is : \code ... diff --git a/doc/doxygen/medloader.dox b/doc/doxygen/medloader.dox index 3204abfb0..9cb490e52 100644 --- a/doc/doxygen/medloader.dox +++ b/doc/doxygen/medloader.dox @@ -3,16 +3,355 @@ \section MEDLoaderIntro Introduction -MEDLoader is a package in charge of loading a file or write to a file +MEDLoader is a package in charge of loading from a file or write to a file in MED format a \ref medcoupling data structure. The fact that these -functionalities are not merged in \ref medcoupling is explained by the -fact of reducing as much as possible the dependancies of \ref -medcoupling libraries. - -The main aim of this package is to propose as much as possible a -complete API in order to fetch data from a MED file. As a MED file can -combine several \ref medcoupling aspects in one (for exemple -unstructured meshes) the API of MEDLoader is much more rich than -simply read and write. +functionalities are not merged in \ref medcoupling is explained by a +willingness of reducing as much as possible the dependancies of \ref medcoupling libraries. + +As a MED file can combine several \ref medcoupling aspects in one (for exemple meshes in +MED file on different mesh dimension with families and groups) the API of MEDLoader is much more rich than simply read and write. + +MEDLoader offers \b static methods whose method names have the first +character in capital. You are intended to use these methods. The following +chapters will try to describe in details some of important ones. + +The basic idea of MEDLoader is to exploite as much as possible MED +file capabilities to store MEDCoupling data file in a MED file and +reversely to load from a MED file into a MEDCoupling data structure. +Basically, the info on components of ParaMEDMEM::DataArrayDouble +instances are stores into components and units into MED files. The +name of meshes and fields are used by MEDLoader to use it as this into +MED file. A field f with \ref ParaMEDMEM::MEDCouplingTimeDiscretization +"time discretization" set to ONE_TIME, the value of +\c f->getTime(time,iteration,order) are used by MEDLoader to store +identifies the field into MED file. All strings used by MEDLoader to +use it into MED file should fulfill the rules of MED file where length +are limited. +That's why the user should be aware of these constaints when trying to read/write a MED file using MEDLoader. +MEDLoader tries to manage that by protecting the user by throwing exceptions when the rules are not followed. + +\section MEDLoaderMainC Main concepts of MED files + +Here we will describes some of basic concepts of MED files in order to +use the best methods proposed by MEDLoader API. + +\subsection MEDLoaderMEDFileGen Basics in MED files + +First of all MEDLoader \b will \b not read MED files whose version is +\b lower \b than \b 2.2. The MEDLoader::CheckFileForRead will perform +the check of that before any attempt of read. + + +For new comers in MED file world some of basics principles are +recalled here. Let's recall basic principles that explains some of the aspect of MEDLoade API. +\anchor MEDLoaderMeshNameConstraint MED file can contain several meshes. These meshes are +discriminated by their names (two meshes could not have the same +names). By the same way a MED file can contain several fields in MED. +So MEDLoader propose to you the MEDLoader::GetMeshNames method to +discover all the mesh names contained in your file. + +A field is also discriminated by its name. The method MEDLoader::GetCellFieldNamesOnMesh and MEDLoader::GetNodeFieldNamesOnMesh are available to know all fields +respectively on cells and on nodes lying on a specified mesh. + + A field is defined by several time steps discriminated by a pair of int +(iteration,order). It is \b not possible to store 2 time steps of a same +field having the same iteration and order +number. The floatting point value attached on this couple of ids (iteration,order) is only present for information. +Static methods MEDLoader::GetCellFieldIterations and +MEDLoader::GetNodeFieldIterations return a vector of pair containing +each respectively iteration and order. + +A time step of a field lyies on one \b or \b more mesh(es) specified by its \b or \b their name. A time step of a field in +MED file could be defined on point \b and on cell \b and, \b or on gauss points \b and, \b or on point per element. + +This recalled specificities of MED file explains that it is necessary to specify +each time, at field-read time, the type of field, the iteration and order +number the mesh you are interested in. + +\subsection MEDLoaderMEDFileMesh Meshes in MED files + +In MED file meshes could combine in one unstructured mesh cells that +have different dimension. For example it is possible to mix +MED_TETRA4, MED_TRIA6, MED_SEG2, MED_POINT0, MED_POLYGON, +MED_POLYHEDRA in a same mesh. In MEDCouplingUMesh such a mix is not +allowed as described \ref MEDCouplingUMeshes "here". So to \b read such mesh it +is important to know which meshdimension you are interested to. In API +the parameter \b meshDimRelToMax discreminates the meshdim you are +interested to relatively to the maximal dimension of cells contained +in the mesh in file. + +Let's take 2 examples : + +- If you have a mesh called "MyMesh" in file "file1.med" with +MED_POLYGON, MED_TRI3, MED_SEG2 and MED_SEG3 : The max dimension of +cells is 2 (for MED_POLYGON and MED_TRI3). So if you want exclusively +cells with type MED_POLYGON and MED_TRI3 you should use : + +\code +MEDCouplingUMesh *m2D=MEDLoader::ReadUMeshFromFile("file1.med","MyMesh",0); +\endcode + +If you are interested in MED_SEG2 and MED_SEG3 you should use : + +\code +MEDCouplingUMesh *m1D=MEDLoader::ReadUMeshFromFile("file1.med","MyMesh",-1); +\endcode + +The method MEDLoader::ReadUMeshDimFromFile could +help you to have this mesh dimension. +\anchor MEDLoaderExample2 +- Consider an another mesh called "Example2" in file "file2.med" +containing MED_POLYHEDRA, MED_TETRA4, MED_QUAD8, MED_TRI6, MED_SEG2 +and MED_POINT0. In this case you will have : + +\code +assert(3==MEDLoader::ReadUMeshDimFromFile("file2.med","Example2")); +\endcode + +To get 3D cells (MED_POLYHEDRA and MED_TETRA4) you should type : +\code +MEDCouplingUMesh *m3D=MEDLoader::ReadUMeshFromFile("file2.med","Example2",0); +\endcode + +To get 2D cells (MED_TRI6 and MED_QUAD8) you should type : + +\code +MEDCouplingUMesh *m2D=MEDLoader::ReadUMeshFromFile("file2.med","Example2",-1); +\endcode + +To get 1D cells (MED_SEG2) you should type : + +\code +MEDCouplingUMesh *m1D=MEDLoader::ReadUMeshFromFile("file2.med","Example2",-2); +\endcode + +And finally for 0D cells (MED_POINT0) you will write : + +\code +MEDCouplingUMesh *m0D=MEDLoader::ReadUMeshFromFile("file2.med","Example2",-3); +\endcode + +To finish this subsection, it is important to know that MEDLoader +takes into account of the cell numbers stored in a mesh of a med +file. This renumbering allows MEDLoader to conserve the order of +MEDCoupling cells into the file. So if the renumbering of cells in MED +file is not correct an exception will be thrown. + +\subsection MEDLoaderMEDFilePoMesh Part of meshes in MED files + +A mesh contains one or more families on nodes and/or on cells. A family is a partition +(mathematical sense) of the mesh it lies to. A family can be described +by an integer field on \b all nodes and on \b all cells of a same mesh. +All cells and nodes having the same ids defines this family. This id +is called the familyId. A family is discriminated by its id. MED file +attach a name to its id to be more userfriendly. So by construction, 2 different +families could not share anything. The user can retrieve all the +families names available on a mesh with the static method MEDLoader::GetMeshFamiliesNames. + +A group is a set of families. So groups can overlap each other, +contrary to families. Groups are also discriminated by a name. As for +families the static method to retrieves the groups of a specified mesh is MEDLoader::GetMeshGroupsNames. + +MEDLoader allows you to retrieve the +corresponding "part of meshes" thanks to static methods +MEDLoader::ReadUMeshFromFamilies and MEDLoader::ReadUMeshFromGroups. +This method allows you to combine several families and groups in the +same returned mesh. + +\subsection MEDLoaderMEDFileField Reading a field at one time step in MED files + +A field at one time step on one mesh, with one entity (cell, node) +lies on all mesh on on a part of it. In this last case a definition of +a profile is needed. Even if the notions of profile on mesh and group +on mesh could appear close, these two concepts are totally +disconnected in MED file. +The aspect of profile is managed by MEDLoader, thats why this +aspect does not appear in the MEDLoader API. +So to retrieve a field on 3D cell called "F1Cell" in example file +\ref MEDLoaderExample2 "file2.med (seen in meshes section)" on a mesh "Example2" on time +step defined by iteration number 2 and iteration 3 the request will be : + +\code +MEDCouplingFieldDouble *f1Cell_3D=MEDLoader::ReadFieldCell("file2.med","Example2",0,"F1Cell",2,3); +\endcode + +To retrive the same field (same iteration) on 2D cells only the call will be : + +\code +MEDCouplingFieldDouble *f1Cell_2D=MEDLoader::ReadFieldCell("file2.med","Example2",-1,"F1Cell",2,3); +\endcode + +\subsection MEDLoaderMEDFieldsRead Reading several field time steps at a time in MED files + +It is possible with MEDLoader to read several time steps of a field at +a time. +The advantage with this approach is to avoid to read and load several +time a same mesh. This is typically recommanded to use the following +code when you desire to load all time steps of a field on cell "myField" lying on +same mesh "mesh1" in one shot : + +\code + +std::vector > timeStepsIds=MEDLoader::GetCellFieldIterations("file4.med"); +std::vector fs=MEDLoader::ReadFieldsCellOnSameMesh("file4.med","mesh1",0,"myField",timeStepsIds); + +\endcode + +\section MEDLoaderWriteMain Writing a MED file with MEDLoader + +As MEDMEM and MED file do, MEDLoader write process separates clearly +meshes from fields. The reason is that a common use case in write mode +is to write in a first time a mesh and then writes several time steps +of a same field in appended mode. + +The fact that the write process is rarely in a one shot put a +constraint on API (as MEDMEM does) to precise to MEDLoader if you intend +to append data to an existing file, or if you want to create a new +file from scratch. This explains the presence of boolean parameter \b +writeFromScratch in API of MEDLoader starting with \b +MEDLoader::Write* . + +If \b writeFromScratch parameter is set to \b true and if the file +already exists the file will be crashed and replaced by the new +corresponding data. If \b writeFromScratch parameter is set to \b false and if the +file does \b not \b exist the new file is created, but if the file +exists MEDLoader will enter in appended mode. + +Two classes of MEDLoader write methods exists when \b writeFromScratch +is set to \b false : + +- Methods \b MEDLoader::Write*Dep : The behaviour is as MEDMEM, that + is to say, the write is done without any question in file. The + responsability is let to the user because the MED file could be + corrupted. The advantage of this method is that it is faster + because no check is done. +- Methods \b MEDLoader::Write* : MEDLoader will not corrupt your file + by always trying to append data. The consequence of that is that a + read of part (and data processing) of MED file could be needed before any attempt of + writing. So these methods could be in some cases much time and memory consuming. + +The behaviour of MEDLoader when \b writeFromScratch is set to false will be precised +for each \b MEDLoader::Write* methods is the next subsections. + +\subsection MEDLoaderWriteMesh Writing one mesh in a MED file with MEDLoader + +The first think to know is that MEDLoader is using the \b meshName in +ParaMEDMEM::MEDCouplingMesh instance to put it in MED file. + +As explained in previous section \ref MEDLoaderMeshNameConstraint "here", +a mesh in MED file is discriminated by a name, so the \b meshName +\b should \b be \b non \b empty. If it is the case an +INTERP_KERNEL::Exception will be thrown. + +To write one mesh \b myMesh with name \b "myMeshName" in a MED file \b "wfile1.med" the following code should be typed : + +\code + +MEDCouplingUMesh *myMesh=...; +myMesh->setName("myMeshName"); +MEDLoader::WriteUMesh("wFile1.med",myMesh,true); + +\endcode + +With the previous code, if "wFile1.med" file existed the file is +crashed and will contain after the call only the content of myMesh +instance. + +If you desire to append a mesh in "wFile1.med" you should type : + +\code + +MEDCouplingUMesh *myMesh=...; +myMesh->setName("myMeshName"); +MEDLoader::WriteUMesh("wFile1.med",myMesh,false); + +\endcode + +With the previous code, if the "wFile1.med" had already a mesh called "myMeshName" an +INTERP_KERNEL::Exception will be thrown. + +\subsection MEDLoaderWriteMeshes Writing several meshes in a MED file with MEDLoader + +It could be interesting to write several meshes in one shot. Two +possiblities are possible : + +- Write several instances of ParaMEDMEM::MEDCouplingUMesh + lying \b on \b same \b coords \b with \b different \b mesh \b dimension. In this case the + use of MEDLoader::WriteUMeshes is the method you should + use. Typically this method should be used to write such of file + defined \ref MEDLoaderExample2 "here". + This method first checks that all instances share the same + ParaMEDMEM::DataArrayDouble instance as coords. If not an + INTERP_KERNEL::Exception will be thrown and an invocation on + ParaMEDMEM::MEDCouplingPointSet::tryToShareSameCoords will be necessary. + +- Write a partition of meshes having \b same \b mesh \b dimension, that is to say a set of + groups and families from given meshes. As in the previous case the + check of same coords will be done (if not an INTERP_KERNEL::Exception is + thrown). After this step this method will + merge (by concerving the order in input) and will simplify the + merged mesh. After this operation, the groups will be constituted by + assigning the groups names with the conresponding names of + instance. That's why all meshes have to have a not empty name and + different each other. The method to use in this case is + MEDLoader::WriteUMeshesPartition. + +For these 2 described methods the semantic of \b writeFromScratch when +\b false is the same, that is to say : no writing +(INTERP_KERNEL::Exception thrown) will be done if the +file already exists and contains already a mesh with name 'meshName' +for MEDLoader::WriteUMeshesPartition method and the name of the first +of the vector of unstructured meshes passed as first parameter of +MEDLoader::WriteUMeshes. + +\subsection MEDLoaderWriteField Writing one time step of a field in a MED file with MEDLoader + +To write \b one \b time \b step of a field from scratch with MEDLoader is to +use MEDLoader::WriteField method. The behviour of this method depends +on the value of the \b writeFromScratch paramter : + +- When \b writeFromScratch equals to \b true, this method performs two things, it +writes the underlying mesh and write the specified time step on it. + +- When \b writeFromScatch equals to \b false, this method looks that + the underlying mesh exists (by looking the content of \c field->getMesh()->getName() ) in file. If not, the behaviour is the + same that previous case with \b writeFromScratch parameter set to + \b true. If the mesh already exists, MEDLoader reads the field and + tries to apply field on it. This operation could be rather time + consuming because a read operation is performed and a reorder + operation too. If the file already contains the same field at the + same time step (iteration and order ids) the corresponding time step + will be replaced by the field passed in parameter. + +\subsection MEDLoaderWriteFields Writing several time steps of a field in a MED file with MEDLoader + +To write a serie of time steps in a "file3.med" file lying on the same +unstructured mesh the typical code +to write is the following : + +\code + +MEDCouplingFieldDouble *f=...; +MEDLoader::WriteUMesh("file3.med",static_castf->getMesh(),true); +f->setTime(1.2,1,0); +//Writing first time step with iteration==1 and order==0 +MEDLoader::WriteFieldUsingAlreadyWrittenMesh("file3.med",f); +f->setTime(1.3,2,0); +f->applyFunc("sqrt(x)"); +//Writing second time step with iteration==2 and order==0 +MEDLoader::WriteFieldUsingAlreadyWrittenMesh("file3.med",f); + +\endcode + +In the previous code, it is important to note that the values of pair +(iteration,order) should be different between two calls to avoid that +a call to MEDLoader::WriteFieldUsingAlreadyWrittenMesh overwrites a +previous call. +An another important thing is the fact that \c f->getMesh() does not be +modified. +This method of writing presents the big advantage to be fast, because +no check neither read is performed by this method. That's why contrary +to other MEDLoader::Write* method the parameter of \b writeFromScratch +is not needed here. */