Coprocessing example: Difference between revisions

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(Update CMakeLists.txt for paraview modularization before 4.0 release.)
 
(5 intermediate revisions by the same user not shown)
Line 59: Line 59:
   if (argc < 3)
   if (argc < 3)
     {
     {
     printf("Usage: %s <cp python file> <number of steps>\n", argv[0]);
     printf("Usage: %s <python coprocessing script> <number of time steps>\n", argv[0]);
     return 1;
     return 1;
     }
     }
Line 137: Line 137:
FIND_PACKAGE(ParaView REQUIRED)
FIND_PACKAGE(ParaView REQUIRED)
INCLUDE(${PARAVIEW_USE_FILE})
INCLUDE(${PARAVIEW_USE_FILE})
INCLUDE_DIRECTORIES(${VTK_MPI_INCLUDE_DIR})
IF(NOT VTK_MPI_INCLUDE_DIR)
  MESSAGE(SEND_ERROR "Must build ParaView with MPI.")
ENDIF()


ADD_EXECUTABLE(CoProcessingExample CoProcessingExample.cxx)
ADD_EXECUTABLE(CoProcessingExample CoProcessingExample.cxx)
TARGET_LINK_LIBRARIES(CoProcessingExample vtkCoProcessor)
TARGET_LINK_LIBRARIES(CoProcessingExample vtkCoProcessorImplementation)
</source>
</source>


Line 172: Line 167:
     timestep = datadescription.GetTimeStep()
     timestep = datadescription.GetTimeStep()


     Sphere1 = CreateProducer( datadescription, "input" )
     grid = CreateProducer( datadescription, "input" )
     ParallelPolyDataWriter1 = CreateWriter( XMLPPolyDataWriter, "input_grid_%t.pvtp", 1, cp_writers )
     ParallelPolyDataWriter1 = CreateWriter( XMLPPolyDataWriter, "input_grid_%t.pvtp", 1, cp_writers )


Line 187: Line 182:


def GetNextProxyToDelete():
def GetNextProxyToDelete():
     iter = servermanager.vtkSMProxyIterator()
     proxyiterator = servermanager.ProxyIterator()
     iter.Begin()
     for proxy in proxyiterator:
    while not iter.IsAtEnd():
        group = proxyiterator.GetGroup()
      if iter.GetGroup().find("prototypes") != -1:
        if group.find("prototypes") != -1:
        iter.Next()
            continue
        continue
        if group != 'timekeeper' and group.find("pq_helper_proxies") == -1 :
      proxy = servermanager._getPyProxy(iter.GetProxy())
            return proxy
      proxygroup = iter.GetGroup()
      iter.Next()
      if proxygroup != 'timekeeper' and proxy != None and proxygroup.find("pq_helper_proxies") == -1 :
          return proxy
 
     return None
     return None


Line 204: Line 194:
     "Creates a producer proxy for the grid"
     "Creates a producer proxy for the grid"
     if not datadescription.GetInputDescriptionByName(gridname):
     if not datadescription.GetInputDescriptionByName(gridname):
      raise RuntimeError, "Simulation input name '%s' does not exist" % gridname
        raise RuntimeError, "Simulation input name '%s' does not exist" % gridname
     grid = datadescription.GetInputDescriptionByName(gridname).GetGrid()
     grid = datadescription.GetInputDescriptionByName(gridname).GetGrid()
     producer = TrivialProducer()
     producer = TrivialProducer()
Line 218: Line 208:
     cp_writers.append(writer)
     cp_writers.append(writer)
     return writer
     return writer
</source>
</source>
----
----
This second script is still rather simple and only performs a cut on the input from
 
the simulation code. It demonstrates though how desired results can be obtained
This second script is still rather simple and only performs a cut on the input from the simulation code. It demonstrates though how desired results can be obtained while performing coprocessing at specified time steps.
while performing coprocessing at specified time steps.


<source lang="python">
<source lang="python">
Line 244: Line 235:
     timestep = datadescription.GetTimeStep()
     timestep = datadescription.GetTimeStep()


     filename_0_pvtp = CreateProducer( datadescription, "input" )
     grid = CreateProducer( datadescription, "input" )
 
     Clip2 = Clip( guiName="Clip2", InsideOut=0, UseValueAsOffset=0, Scalars=['POINTS', 'Elevation'], Value=0.0, ClipType="Plane" )
     Clip2 = Clip( guiName="Clip2", InsideOut=0, UseValueAsOffset=0, Scalars=['POINTS', 'Elevation'], Value=0.0, ClipType="Plane" )
     Clip2.ClipType.Normal = [0.0, 1.0, 0.0]
     Clip2.ClipType.Normal = [0.0, 1.0, 0.0]
Line 264: Line 254:


def GetNextProxyToDelete():
def GetNextProxyToDelete():
     iter = servermanager.vtkSMProxyIterator()
     proxyiterator = servermanager.ProxyIterator()
     iter.Begin()
     for proxy in proxyiterator:
    while not iter.IsAtEnd():
        group = proxyiterator.GetGroup()
      if iter.GetGroup().find("prototypes") != -1:
        if group.find("prototypes") != -1:
        iter.Next()
            continue
        continue
        if group != 'timekeeper' and group.find("pq_helper_proxies") == -1 :
      proxy = servermanager._getPyProxy(iter.GetProxy())
            return proxy
      proxygroup = iter.GetGroup()
      iter.Next()
      if proxygroup != 'timekeeper' and proxy != None and proxygroup.find("pq_helper_proxies") == -1 :
          return proxy
 
     return None
     return None


def CreateProducer(datadescription, gridname):
def CreateProducer(datadescription, gridname):
  "Creates a producer proxy for the grid"
    "Creates a producer proxy for the grid"
  if not datadescription.GetInputDescriptionByName(gridname):
    if not datadescription.GetInputDescriptionByName(gridname):
    raise RuntimeError, "Simulation input name '%s' does not exist" % gridname
        raise RuntimeError, "Simulation input name '%s' does not exist" % gridname
  grid = datadescription.GetInputDescriptionByName(gridname).GetGrid()
    grid = datadescription.GetInputDescriptionByName(gridname).GetGrid()
  producer = TrivialProducer()
    producer = TrivialProducer()
  producer.GetClientSideObject().SetOutput(grid)
    producer.GetClientSideObject().SetOutput(grid)
  producer.UpdatePipeline()
    producer.UpdatePipeline()
  return producer
    return producer


def CreateWriter(proxy_ctor, filename, freq, cp_writers):
def CreateWriter(proxy_ctor, filename, freq, cp_writers):

Latest revision as of 01:56, 14 September 2012

This example is used to demonstrate how the co-processing library can be used with a C++ based simulation code. In the ParaView/CoProcessing/Adaptors/FortranAdaptors directory there is code useful for integrating C or Fortran based simulation codes withthe co-processing library. Note that this example requires MPI to be available on your system. The executable takes in a python coprocessing script and a number of time steps to be run for. Note to remember to set your system environment properly. See [[1]] for details.


CoProcessingExample.cxx

<source lang="cpp">

  1. include "vtkCPDataDescription.h"
  2. include "vtkCPInputDataDescription.h"
  3. include "vtkCPProcessor.h"
  4. include "vtkCPPythonScriptPipeline.h"
  5. include "vtkElevationFilter.h"
  6. include "vtkPolyData.h"
  7. include "vtkSmartPointer.h"
  8. include "vtkSphereSource.h"
  9. include "vtkXMLUnstructuredGridReader.h"
  1. include <mpi.h>
  2. include <string>

class DataGenerator { public:

 DataGenerator()
   {
   this->Sphere = vtkSmartPointer<vtkSphereSource>::New();
   this->Sphere->SetThetaResolution(30);
   this->Sphere->SetPhiResolution(30);
   int procId;
   MPI_Comm_rank(MPI_COMM_WORLD, &procId);
   this->Sphere->SetCenter(procId*4.0, 0, 0);
   this->Elevation = vtkSmartPointer<vtkElevationFilter>::New();
   this->Elevation->SetInputConnection(this->Sphere->GetOutputPort());
   this->Index = 0;
   }
 vtkSmartPointer<vtkPolyData> GetNext()
   {
   double radius = fabs(sin(0.1 * this->Index));
   this->Index++;
   this->Sphere->SetRadius(1.0 + radius);
   this->Elevation->Update();
   vtkSmartPointer<vtkPolyData> ret = vtkSmartPointer<vtkPolyData>::New();
   ret->DeepCopy(this->Elevation->GetOutput());
   return ret;
   }

protected:

 int Index;
 vtkSmartPointer<vtkSphereSource> Sphere;
 vtkSmartPointer<vtkElevationFilter> Elevation;

};

int main(int argc, char* argv[]) {

 if (argc < 3)
   {
   printf("Usage: %s <python coprocessing script> <number of time steps>\n", argv[0]);
   return 1;
   }
 // we assume that this is done in parallel
 MPI_Init(&argc, &argv);
 std::string cpPythonFile = argv[1];
 int nSteps = atoi(argv[2]);
 vtkCPProcessor* processor = vtkCPProcessor::New();
 processor->Initialize();
 vtkCPPythonScriptPipeline* pipeline = vtkCPPythonScriptPipeline::New();
 // read the coprocessing python file
 if(pipeline->Initialize(cpPythonFile.c_str()) == 0)
   {
   cout << "Problem reading the python script.\n";
   return 1;
   }
 processor->AddPipeline(pipeline);
 pipeline->Delete();
 if (nSteps == 0)
   {
   return 0;
   }
 // create a data source, typically this will come from the adaptor
 // but here we use generator to create it ourselves
 DataGenerator generator;
 // do coprocessing
 double tStart = 0.0;
 double tEnd = 1.0;
 double stepSize = (tEnd - tStart)/nSteps;
 vtkCPDataDescription* dataDesc = vtkCPDataDescription::New();
 dataDesc->AddInput("input");
 for (int i = 0; i < nSteps; ++i)
   {
   double currentTime = tStart + stepSize*i;
   // set the current time and time step
   dataDesc->SetTimeData(currentTime, i);
   // check if the script says we should do coprocessing now
   if(processor->RequestDataDescription(dataDesc) != 0)
     {
     // we are going to do coprocessing so use generator to
     // create our grid at this timestep and provide it to
     // the coprocessing library
     vtkSmartPointer<vtkDataObject> dataObject =
       generator.GetNext();
     dataDesc->GetInputDescriptionByName("input")->SetGrid(dataObject);
     processor->CoProcess(dataDesc);
     }
   }
 dataDesc->Delete();
 processor->Finalize();
 processor->Delete();
 MPI_Finalize();
 return 0;

} </source>

CMakeLists.txt

<source lang="cmake"> cmake_minimum_required(VERSION 2.6)

PROJECT(CoProcessingExample)

FIND_PACKAGE(ParaView REQUIRED) INCLUDE(${PARAVIEW_USE_FILE})

ADD_EXECUTABLE(CoProcessingExample CoProcessingExample.cxx) TARGET_LINK_LIBRARIES(CoProcessingExample vtkCoProcessorImplementation) </source>

Python Scripts

The first python script below is used to just output the actual results of the example. This would correspond to a simulation run with a coarse grid in order to set up coprocessing runs for larger grids where outputting the entire simulation results can be computationally prohibitive.

<source lang="python"> try: paraview.simple except: from paraview.simple import *

def RequestDataDescription(datadescription):

   "Callback to populate the request for current timestep"
   timestep = datadescription.GetTimeStep()
   input_name = 'input'
   if (timestep % 1 == 0) :
       datadescription.GetInputDescriptionByName(input_name).AllFieldsOn()
       datadescription.GetInputDescriptionByName(input_name).GenerateMeshOn()
   else:
       datadescription.GetInputDescriptionByName(input_name).AllFieldsOff()
       datadescription.GetInputDescriptionByName(input_name).GenerateMeshOff()

def DoCoProcessing(datadescription):

   "Callback to do co-processing for current timestep"
   cp_writers = []
   timestep = datadescription.GetTimeStep()
   grid = CreateProducer( datadescription, "input" )
   ParallelPolyDataWriter1 = CreateWriter( XMLPPolyDataWriter, "input_grid_%t.pvtp", 1, cp_writers )
   for writer in cp_writers:
       if timestep % writer.cpFrequency == 0:
           writer.FileName = writer.cpFileName.replace("%t", str(timestep))
           writer.UpdatePipeline()
   # explicitly delete the proxies -- we do it this way to avoid problems with prototypes
   tobedeleted = GetNextProxyToDelete()
   while tobedeleted != None:
       Delete(tobedeleted)
       tobedeleted = GetNextProxyToDelete()

def GetNextProxyToDelete():

   proxyiterator = servermanager.ProxyIterator()
   for proxy in proxyiterator:
       group = proxyiterator.GetGroup()
       if group.find("prototypes") != -1:
           continue
       if group != 'timekeeper' and group.find("pq_helper_proxies") == -1 :
           return proxy
   return None

def CreateProducer(datadescription, gridname):

   "Creates a producer proxy for the grid"
   if not datadescription.GetInputDescriptionByName(gridname):
       raise RuntimeError, "Simulation input name '%s' does not exist" % gridname
   grid = datadescription.GetInputDescriptionByName(gridname).GetGrid()
   producer = TrivialProducer()
   producer.GetClientSideObject().SetOutput(grid)
   producer.UpdatePipeline()
   return producer

def CreateWriter(proxy_ctor, filename, freq, cp_writers):

   writer = proxy_ctor()
   writer.FileName = filename
   writer.add_attribute("cpFrequency", freq)
   writer.add_attribute("cpFileName", filename)
   cp_writers.append(writer)
   return writer

</source>


This second script is still rather simple and only performs a cut on the input from the simulation code. It demonstrates though how desired results can be obtained while performing coprocessing at specified time steps.

<source lang="python"> try: paraview.simple except: from paraview.simple import *

def RequestDataDescription(datadescription):

   "Callback to populate the request for current timestep"
   timestep = datadescription.GetTimeStep()
   input_name = 'input'
   if (timestep % 5 == 0) :
       datadescription.GetInputDescriptionByName(input_name).AllFieldsOn()
       datadescription.GetInputDescriptionByName(input_name).GenerateMeshOn()
   else:
       datadescription.GetInputDescriptionByName(input_name).AllFieldsOff()
       datadescription.GetInputDescriptionByName(input_name).GenerateMeshOff()

def DoCoProcessing(datadescription):

   "Callback to do co-processing for current timestep"
   cp_writers = []
   timestep = datadescription.GetTimeStep()
   grid = CreateProducer( datadescription, "input" )
   Clip2 = Clip( guiName="Clip2", InsideOut=0, UseValueAsOffset=0, Scalars=['POINTS', 'Elevation'], Value=0.0, ClipType="Plane" )
   Clip2.ClipType.Normal = [0.0, 1.0, 0.0]
   Clip2.ClipType.Origin = [1.9999999105930328, 0.0, 0.0]
   Clip2.ClipType.Offset = 0.0
   ParallelUnstructuredGridWriter2 = CreateWriter( XMLPUnstructuredGridWriter, "Cut_%t.pvtu", 5, cp_writers )
   for writer in cp_writers:
       if timestep % writer.cpFrequency == 0:
           writer.FileName = writer.cpFileName.replace("%t", str(timestep))
           writer.UpdatePipeline()
   # explicitly delete the proxies -- we do it this way to avoid problems with prototypes
   tobedeleted = GetNextProxyToDelete()
   while tobedeleted != None:
       Delete(tobedeleted)
       tobedeleted = GetNextProxyToDelete()

def GetNextProxyToDelete():

   proxyiterator = servermanager.ProxyIterator()
   for proxy in proxyiterator:
       group = proxyiterator.GetGroup()
       if group.find("prototypes") != -1:
           continue
       if group != 'timekeeper' and group.find("pq_helper_proxies") == -1 :
           return proxy
   return None

def CreateProducer(datadescription, gridname):

   "Creates a producer proxy for the grid"
   if not datadescription.GetInputDescriptionByName(gridname):
       raise RuntimeError, "Simulation input name '%s' does not exist" % gridname
   grid = datadescription.GetInputDescriptionByName(gridname).GetGrid()
   producer = TrivialProducer()
   producer.GetClientSideObject().SetOutput(grid)
   producer.UpdatePipeline()
   return producer

def CreateWriter(proxy_ctor, filename, freq, cp_writers):

   writer = proxy_ctor()
   writer.FileName = filename
   writer.add_attribute("cpFrequency", freq)
   writer.add_attribute("cpFileName", filename)
   cp_writers.append(writer)
   return writer

</source>