//- write force displacement to file
if(historyPatchID != -1)
  {
    Info << "Writing disp and force of patch "<<historyPatchName<<" to file"
	  << endl;

     //- for small strain or moving mesh
    vector force = gSum(mesh.boundary()[historyPatchID].Sf() & sigma.boundaryField()[historyPatchID]);
     
     //- for large strain total lagrangian
     // tensorField F = I + gradU.boundaryField()[historyPatchID];
     // vectorField totalForce = mesh.Sf().boundaryField()[historyPatchID] & (sigma.boundaryField()[historyPatchID] & F);
     
     //vector force = sum( totalForce );
     
     //scalar force = force[vector::Y];;
     
     //- patchIntegrate utility integrates it this way but this is worng because the sigma tensor should
     //- be dotted with the surface normal to give the actual traction/force
     //- you cannot just take the component of the sigma tensor
     //scalar forcePatchIntegrateMethod = gSum(
     //					    mesh.magSf().boundaryField()[historyPatchID]
     //					    *sigma.boundaryField()[historyPatchID].component(symmTensor::XY)
     //					    );
     
     vector avDisp = gAverage(U.boundaryField()[historyPatchID]);
     
     //- write to file
     if(Pstream::master())
       {
	 OFstream& forceDispFile = *filePtr;
	 forceDispFile << avDisp.x() << " " << avDisp.y() << " " << avDisp.z() << " "
		       << force.x() << " " << force.y() << " " << force.z() << endl;
       }
   }

if(clipGPtr)
  {
    clipGPtr->write();
  }