Computational routine
eng

##
mat_bksl

### File content

    # include "scicos_block4.h"
    # include "../machine.h"
    #include <stdio.h>
    #include <math.h>
    extern int C2F(dgetrf)();
    extern double C2F(dlamch)();
    extern double C2F(dlange)();
    extern int C2F(dlacpy)();
    extern int C2F(dgecon)();
    extern int C2F(dgetrs)();
    extern int C2F(dgelsy1)();

    #if WIN32
    #define NULL    0
    #endif

    #ifndef min
    #define min(a,b) ((a) <= (b) ? (a) : (b))
    #endif

    #ifndef max
    #define max(a,b) ((a) >= (b) ? (a) : (b))
    #endif

    typedef struct
    {         int *ipiv;
              int *rank;
              int *jpvt;
              int *iwork;
              double *dwork;
    	  double *LAF;
    	  double *LA;
    	  double *LXB;
    } mat_bksl_struct ;
    void mat_bksl(scicos_block *block,int flag)
    {
     double *u1;
     double *u2;
     double *y;
     int mu;
     int nu1;
     int nu2;
     int info;
     int i,l,lw,lu;
     mat_bksl_struct *ptr;
     double rcond, ANORM, EPS;

     mu =GetInPortRows(block,1);
     nu1 =GetInPortCols(block,1);
     nu2 =GetInPortCols(block,2);
     u1=GetRealInPortPtrs(block,1);
     u2=GetRealInPortPtrs(block,2);
     y=GetRealOutPortPtrs(block,1);
     l=max(mu,nu1);
     lu=max(4*nu1,min(mu,nu1)+3*nu1+1);
     lw=max(lu,2*min(mu,nu1)+nu2);
                 /*init : initialization*/
    if (flag==4)
       {if((*(block->work)=(mat_bksl_struct*) scicos_malloc(sizeof(mat_bksl_struct)))==NULL)
    	{set_block_error(-16);
    	 return;}
        ptr=*(block->work);
        if((ptr->ipiv=(int*) scicos_malloc(sizeof(int)*nu1))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr);
    	 return;}
        if((ptr->rank=(int*) scicos_malloc(sizeof(int)))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr->ipiv);
    	 scicos_free(ptr);
    	 return;}
        if((ptr->jpvt=(int*) scicos_malloc(sizeof(int)*nu1))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr->rank);
    	 scicos_free(ptr->ipiv);
    	 scicos_free(ptr);
    	 return;}
        if((ptr->iwork=(int*) scicos_malloc(sizeof(int)*nu1))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr->jpvt);
    	 scicos_free(ptr->rank);
    	 scicos_free(ptr->ipiv);
    	 scicos_free(ptr);
    	 return;}
        if((ptr->dwork=(double*) scicos_malloc(sizeof(double)*lw))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr->iwork);
    	 scicos_free(ptr->jpvt);
    	 scicos_free(ptr->rank);
    	 scicos_free(ptr->ipiv);
    	 scicos_free(ptr);
    	 return;}
        if((ptr->LAF=(double*) scicos_malloc(sizeof(double)*(mu*nu1)))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr->dwork);
    	 scicos_free(ptr->iwork);
    	 scicos_free(ptr->jpvt);
    	 scicos_free(ptr->rank);
    	 scicos_free(ptr->ipiv);
    	 scicos_free(ptr);
    	 return;}
        if((ptr->LA=(double*) scicos_malloc(sizeof(double)*(mu*nu1)))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr->LAF);
    	 scicos_free(ptr->dwork);
    	 scicos_free(ptr->iwork);
    	 scicos_free(ptr->jpvt);
    	 scicos_free(ptr->rank);
    	 scicos_free(ptr->ipiv);
    	 scicos_free(ptr);
    	 return;}
        if((ptr->LXB=(double*) scicos_malloc(sizeof(double)*(l*nu2)))==NULL)
    	{set_block_error(-16);
    	 scicos_free(ptr->LA);
    	 scicos_free(ptr->LAF);
    	 scicos_free(ptr->dwork);
    	 scicos_free(ptr->iwork);
    	 scicos_free(ptr->jpvt);
    	 scicos_free(ptr->rank);
    	 scicos_free(ptr->ipiv);
    	 scicos_free(ptr);
    	 return;}

       }

           /* Terminaison */
    else if (flag==5)
       {ptr=*(block->work);
        if(ptr->LXB!=NULL){
        	scicos_free(ptr->ipiv);
        	scicos_free(ptr->rank);
        	scicos_free(ptr->jpvt);
        	scicos_free(ptr->iwork);
        	scicos_free(ptr->LAF);
        	scicos_free(ptr->LA);
        	scicos_free(ptr->LXB);
        	scicos_free(ptr->dwork);
        	scicos_free(ptr);
        	return;}
       }

    else
       {
        ptr=*(block->work);
        EPS=C2F(dlamch)("e",1L);
        ANORM=C2F(dlange)("1",&mu,&nu1,u1,&mu,ptr->dwork);
        C2F(dlacpy)("F",&mu,&nu1,u1,&mu,ptr->LA,&mu);
        if (mu==nu1)
    	{C2F(dlacpy)("F",&mu,&nu1,ptr->LA,&mu,ptr->LAF,&mu);
    	 C2F(dgetrf)(&nu1,&nu1,ptr->LAF,&nu1,ptr->ipiv,&info);
    	 rcond=0;
     	 if (info==0)
    	    {C2F(dgecon)("1",&nu1,ptr->LAF,&nu1,&ANORM,&rcond,ptr->dwork,ptr->iwork,&info);
    	     if (rcond>pow(EPS,0.5))
    		{C2F(dlacpy)("F",&nu1,&nu2,u2,&nu1,ptr->LXB,&nu1);
    		 C2F(dgetrs)("N",&nu1,&nu2,ptr->LAF,&nu1,ptr->ipiv,ptr->LXB,&nu1,&info);
    		 C2F(dlacpy)("F",&nu1,&nu2,ptr->LXB,&nu1,y,&nu1);
    		 return;
    		}
    	    }
    	}
        rcond=pow(EPS,0.5);
        C2F(dlacpy)("F",&mu,&nu2,u2,&mu,ptr->LXB,&l);
        for (i=0;i<nu1;i++)    *(ptr->jpvt+i)=0;

        C2F(dgelsy1)(&mu,&nu1,&nu2,ptr->LA,&mu,ptr->LXB,&l,ptr->jpvt,&rcond,ptr->rank,ptr->dwork,&lw,&info);
        if (info!=0)
    	{if (flag!=6)
    	    {set_block_error(-7);
                 return;
    	    }
    	}
        C2F(dlacpy)("F",&nu1,&nu2,ptr->LXB,&l,y,&nu1);
        }
    }