source: issm/trunk/src/c/modules/DragCoefficientAbsGradientx/DragCoefficientAbsGradientx.cpp@ 19105

/*!\file DragCoefficientAbsGradientx
 * \brief: compute misfit between observations and model
 */

#include "./DragCoefficientAbsGradientx.h"

#include "../../shared/shared.h"
#include "../../toolkits/toolkits.h"

void DragCoefficientAbsGradientx( IssmDouble* pJ, Elements* elements,Nodes* nodes, Vertices* vertices, Loads* loads, Materials* materials,Parameters* parameters){

        /*output: */
        IssmDouble J=0.;
        IssmDouble J_sum;

        /*Compute Misfit: */
        for(int i=0;i<elements->Size();i++){
                Element* element=xDynamicCast<Element*>(elements->GetObjectByOffset(i));
                J+=DragCoefficientAbsGradient(element);
        }

        /*Sum all J from all cpus of the cluster:*/
        ISSM_MPI_Reduce (&J,&J_sum,1,ISSM_MPI_DOUBLE,ISSM_MPI_SUM,0,IssmComm::GetComm() );
        ISSM_MPI_Bcast(&J_sum,1,ISSM_MPI_DOUBLE,0,IssmComm::GetComm());
        J=J_sum;

        /*Assign output pointers: */
        *pJ=J;
}

IssmDouble DragCoefficientAbsGradient(Element* element){

        int         domaintype,numcomponents;
        IssmDouble  Jelem=0.;
        IssmDouble  misfit,Jdet;
        IssmDouble  dp[2],weight;
        IssmDouble* xyz_list      = NULL;

        /*Get basal element*/
        if(!element->IsOnBase()) return 0.;

        /*If on water, return 0: */
        if(!element->IsIceInElement()) return 0.;

        /*Get problem dimension*/
        element->FindParam(&domaintype,DomainTypeEnum);
        switch(domaintype){
                case Domain2DverticalEnum:   numcomponents   = 1; break;
                case Domain3DEnum:           numcomponents   = 2; break;
                case Domain2DhorizontalEnum: numcomponents   = 2; break;
                default: _error_("not supported yet");
        }

        /*Spawn basal element*/
        Element* basalelement = element->SpawnBasalElement();

        /* Get node coordinates*/
        basalelement->GetVerticesCoordinates(&xyz_list);

        /*Retrieve all inputs we will be needing: */
        Input* weights_input=basalelement->GetInput(InversionCostFunctionsCoefficientsEnum);   _assert_(weights_input);
        Input* drag_input   =basalelement->GetInput(FrictionCoefficientEnum); _assert_(drag_input);

        /* Start  looping on the number of gaussian points: */
        Gauss* gauss=basalelement->NewGauss(2);
        for(int ig=gauss->begin();ig<gauss->end();ig++){

                gauss->GaussPoint(ig);

                /* Get Jacobian determinant: */
                basalelement->JacobianDeterminant(&Jdet,xyz_list,gauss);

                /*Get all parameters at gaussian point*/
                weights_input->GetInputValue(&weight,gauss,DragCoefficientAbsGradientEnum);
                drag_input->GetInputDerivativeValue(&dp[0],xyz_list,gauss);

                /*Compute Tikhonov regularization J = 1/2 ((dp/dx)^2 + (dp/dy)^2) */
                Jelem+=weight*.5*dp[0]*dp[0]*Jdet*gauss->weight;
                if(numcomponents==2) Jelem+=weight*.5*dp[1]*dp[1]*Jdet*gauss->weight;

        }

        /*clean up and Return: */
        if(domaintype!=Domain2DhorizontalEnum){basalelement->DeleteMaterials(); delete basalelement;};
        xDelete<IssmDouble>(xyz_list);
        delete gauss;
        return Jelem;
}