/************************************
        Extended Kalman Filter
        Matrix operations

        V. Smidl, Z. Peroutka

Rev. 28.10.2010   (ZP)

26.10.2010      Prvni verze (VS)

26.10.2010      Upravena chyba v Thorton_fast - spatne shiftovani o vypoctu SIGMA.
27.10.2010      Pokus o odstraneni problemu v Thorton_fast - potize dela omezovani (orezavani) varianci.
28.10.2010      Drobne upravy v kodu.

*************************************/

#include "matrix_vs.h"
#include <math.h>
#include "matrix.h"

#include <stdio.h>
/* Matrix multiply Full matrix by upper diagonal matrix; */
void mmultAU(int16 *m1, int16 *up, int16 *result, unsigned int16 rows, unsigned int16 columns) {
    unsigned int16 i, j, k;
    int32 tmp_sum=0L; //in 15+qAU
    int16 *m2pom;
    int16 *m1pom=m1;
    int16 *respom=result;

    for (i=0; i<rows; i++) //rows of result
    {
        for (j=0; j<columns; j++) //columns of result
	{
            m2pom=up+j;//??

            for (k=0; k<j; k++) //inner loop up to "j" - U(j,j)==1;
            {
                tmp_sum+=((int32)(*(m1pom++))**m2pom)>>(15-qAU);
                m2pom+=columns;
            }
            // add the missing A(i,j)
            tmp_sum +=(int32)(*m1pom)<<qAU; // no need to shift
            m1pom-=(j); // shift back to first element

            *respom++=tmp_sum>>15;

            tmp_sum=0;
        }
        m1pom+=(columns);
    }
};

//same as mmultAU but different precision
void mmultCU(int16 *m1, int16 *up, int16 *result, unsigned int16 rows, unsigned int16 columns) {
	unsigned int16 i, j, k;
	int32 tmp_sum=0L; //in 15+qAU
	int16 *m2pom;
	int16 *m1pom=m1;
	int16 *respom=result;
	
	for (i=0; i<rows; i++) //rows of result
    {
		for (j=0; j<columns; j++) //columns of result
	{
		m2pom=up+j;//??
		
		for (k=0; k<j; k++) //inner loop up to "j" - U(j,j)==1;
            {
				tmp_sum+=((int32)(*(m1pom++))**m2pom)>>(15-qCU);
				m2pom+=columns;
			}
			// add the missing A(i,j)
			tmp_sum +=(int32)(*m1pom)<<qCU; // no need to shift
			m1pom-=(j); // shift back to first element
			
			*respom++=tmp_sum>>15;
		
		tmp_sum=0;
	}
	m1pom+=(columns);
	}
};


void bierman_fast(int16 *difz, int16 *xp, int16 *U, int16 *D, int16 *R, unsigned int16 dimy, unsigned int16 dimx )
{
    int16 alpha; // in qD!!
    int16 beta,lambda;
    int16 b[5]; // ok even for 4-dim state  // in qD!!!
    int16 *a; // in [0,1] -> q15
    unsigned int16 iy,j,i;

    int16 *b_j,*b_i;
    int16 *a_j;
    int16 *D_j;
    int16 *U_ij;
    int16 *x_i;
	
	int16 Ucopy[16];
	
	/* copy U for vector a */
	int16 *Uc_i=Ucopy;
	int16 *U_i=U;
	for (i=0;i<dimx*dimx;i++) *(Uc_i++)=*(U_i++);

    a = Ucopy; // iyth row of U
    for (iy=0; iy<dimy; iy++, a+=dimx) {
        // a is a row
        for (j=0,a_j=a,b_j=b,D_j=D; j<dimx; j++,b_j++,D_j++,a_j++)
            *b_j=((int32)(*D_j)*(*a_j))>>15;

        alpha = (R[iy])>>(15-qD); //\alpha = R+vDv = R+a*b
        for (j=0,a_j=a,b_j=b,D_j=D; j<dimx; j++,a_j++,b_j++,D_j++) {

			lambda=alpha; // in qD
            alpha  += ((int32)(*a_j)*(*b_j))>>15;
            D[j] = ((int32)lambda**D_j)/alpha;

            if (*D_j==0) *D_j=1;

            for (i=0,b_i=b,U_ij=U+j; i<j; i++, b_i++,U_ij+=dimx) {
                beta   = *U_ij;
                *U_ij -=  ((int32)(*a_j)*(*b_i))/lambda;         // pozadovane optimalni reseni
                *b_i  +=  ((int32)beta*(*b_j))>>15;
            }
        }
        // no shift due to gamma
        for (i=0,x_i=xp,b_i=b; i<dimx; i++,x_i++,b_i++) {
            *x_i  += ((int32)difz[iy]*(*b_i))/alpha; // multiply by unscaled Kalman gain
        }
    }
}

void bierman_fastC(int16 *difz, int16 *xp, int16 *U, int16 *D, int16 *C, int16 *R, unsigned int16 dimy, unsigned int16 dimx )
{
	int16 alpha; // in qD
	int16 beta,lambda;
	int16 b[5]; // ok even for 4-dim state  // in qD
	int16 *a; // in [0,1] -> qCU
	unsigned int16 iy,j,i;
	
	int16 *b_j,*b_i;
	int16 *a_j;
	int16 *D_j;
	int16 *U_ij;
	int16 *x_i;
	
//	int32 z_pom;
//	int16 z_pom_int16;
	
	int16 UC[16]; // in q15
	
	/* copy U for vector a */
	mmultCU(C,U,UC,dimy,dimx);
	
	a = UC; // iyth row of U
	for (iy=0; iy<dimy; iy++, a+=dimx) {
		// a is a row
		for (j=0,a_j=a,b_j=b,D_j=D; j<dimx; j++,b_j++,D_j++,a_j++)
			*b_j=((int32)(*D_j)*(*a_j))>>15; 
		
		alpha = (R[iy])>>(15-qD); //\alpha = R+vDv = R+a*b
		// R in q15, a in q15, b=q15
		//		gamma = (1<<15)/alpha; //(in q15)
		//min alpha = R[iy] = 164
		//max gamma = 0.0061 => gamma_ref = q7
		for (j=0,a_j=a,b_j=b,D_j=D; j<dimx; j++,a_j++,b_j++,D_j++) {
			/*            beta=alpha;
			 *            lambda = -((int32)(*a_j)<<15)/beta;
			 *            alpha  += ((int32)(*a_j)*(*b_j))>>15;
			 *            D[j] = ((int32)beta**D_j)/alpha;*/
			/*xx*/
			lambda=alpha;
			alpha  += ((int32)(*a_j)*(*b_j))>>15;
			D[j] = ((int32)lambda**D_j)/alpha;
//			z_pom_int16 = -((int32)(*a_j)<<15)/lambda;
			/*xx*/
			
			if (*D_j==0) *D_j=1;
			
			for (i=0,b_i=b,U_ij=U+j; i<j; i++, b_i++,U_ij+=dimx) {
				beta   = *U_ij;
				//                *U_ij +=  ((int32)lambda*(*b_i))>>15;		// puvodni reseni
				*U_ij -=  ((int32)(*a_j)*(*b_i))/lambda;         // pozadovane optimalni reseni
				 *b_i  +=  ((int32)beta*(*b_j))>>15;
				 //printf("%d, %d, %d\n", ((int32)(*a_j)*(*b_i))/lambda, *b_i, beta);
			}
		}
		// no shift due to gamma
		for (i=0,x_i=xp,b_i=b; i<dimx; i++,x_i++,b_i++) {
			*x_i  += ((int32)difz[iy]*(*b_i))/alpha; // multiply by unscaled Kalman gain
		}
	}
}

// Thorton procedure - Kalman predictive variance in UD
void thorton(int16 *U, int16 *D, int16 *PSIU, int16 *Q, int16 *G, int16 *Dold, unsigned int16 rows) {
	thorton_fast(U, D, PSIU, Q, G, Dold, rows);
}
	
// Thorton procedure - Kalman predictive variance in UD
void thorton_fast(int16 *U, int16 *D, int16 *PSIU, int16 *Q, int16 *G, int16 *Dold, unsigned int16 rows) {
    unsigned int16 i,j,k;
    // copy D to Dold
    int16 *Dold_i,*Dold_k;
    int16 *D_i;
    int16 *PSIU_ij,*PSIU_ik,*PSIU_jk;
    int16 *Q_jj,*Q_ii,*Q_kk;
    int16 *U_ji;
    int16 *G_ik,*G_jk;
    int16 irows,jrows;
    int32 sigma; // in qAU+qD!!
    int32 z;

    for (i=0,Dold_i=Dold,D_i=D;i<rows;i++,Dold_i++,D_i++) {
        *Dold_i=*D_i;
    }

    // initialize G = eye()
    G_ik= G;
    *G_ik++=32767;
    for (i=0;i<rows-1;i++) {
        // clean elem before diag
        for (k=0; k<rows; k++) {
            *G_ik++=0;
        }
        *G_ik++=32767;
    }
    // eye created

    for (i=rows-1, Dold_i=Dold+i, D_i=D+i;
            1; i--, Dold_i--,D_i--) { // stop if i==0 at the END!
        irows=i*rows;
        sigma = 0;
        for (k=0, PSIU_ik=PSIU+irows,Dold_k=Dold;
                k<rows; k++, PSIU_ik++,Dold_k++) {
			sigma += (((int32)(*PSIU_ik)**PSIU_ik)>>(qAU))*(*Dold_k);
        }
        sigma += (int32)(*(Q+i+irows))<<(qAU+qD-15);
        for (j=i+1, G_ik=G+irows+i+1; j<rows; j++,G_ik++) {
            sigma += ((((int32)(*G_ik)**G_ik)>>15)**(Q+j+j*rows))>>(30-qAU-qD);
        }

		if (sigma>((int32)1<<(qAU+15))) {
			*D_i = 32767;
//			*(Dold+i)-=*(Q+i+irows);
		} else {
			*D_i=sigma>>qAU;
		}
        if (*D_i==0) *D_i=1;

        for (j=0;j<i;j++) {
            jrows = j*rows;

            sigma =0;
            for (k=0, PSIU_ik=PSIU+irows, PSIU_jk=PSIU+jrows, Dold_k=Dold;
                    k<rows; k++, PSIU_ik++, PSIU_jk++, Dold_k++) {

				sigma += ((((int32)(*PSIU_ik)**PSIU_jk)>>qAU)**Dold_k);
            }

            for (k=i,G_ik=G+irows+i,G_jk=G+jrows+i,Q_kk=Q+k*rows+k;
                    k<rows;k++,G_ik++,G_jk++,Q_kk+=rows+1) {
                sigma += (((((int32)*G_ik)**G_jk)>>15)**Q_kk)>>(30-qD-qAU);
            }

            z=(sigma/(*D_i))<<(15-qAU); // shift to q15
            if (z>32767) z=32767;
            if (z<-32768) z=-32768;

            U_ji=U+jrows+i;
            *U_ji = (int16)z;


            for (k=0,PSIU_ik=PSIU+irows,PSIU_jk=PSIU+jrows;
                    k<rows;k++,PSIU_ik++,PSIU_jk++) {
                *PSIU_jk -= ((int32)*U_ji**PSIU_ik)>>15;
            }

            for (k=0,G_jk=G+jrows,G_ik=G+irows;
                    k<rows;k++, G_jk++, G_ik++) {
                *G_jk -=  ((int32)*U_ji**G_ik)>>15;
            }

        }
		if (i==0) return;
    }
}

void householder(int16 *Ch /*= int16 *PSICh*/, int16 *Q, unsigned int16 dimx) {
    int16 k,j,i;
    int16 alpha,beta;
    int32  sigma; // 2*qCh
    int32  tmp_long;
    int16 B[25];//Q in qCh
    int16 w[5];
    int16 v[5];

    // copy Q to B
    for (i=0;i<dimx*dimx;i++)
    {
        B[i]=Q[i]>>(15-qCh);
    }

    for (k=dimx-1; k>=0; k--)
    {
        sigma=0;
        for (j=0;j<dimx;j++)
        {
            sigma+=((int32)B[k*dimx+j]*B[k*dimx+j]);
        }
        for (j=0;j<=k;j++)
        {
            sigma+=((int32)Ch[k*dimx+j]*Ch[k*dimx+j]);
        }
        
        //alpha in qCh
        alpha = (int16)(sqrt((double)sigma)+0.5);   // predelat pro DSP

		sigma=0;
        for (j=0;j<dimx;j++) {
            w[j]=B[k*dimx+j];
            sigma+=(int32)w[j]*w[j];
        }
        for (j=0; j<=k;j++) {
            if (j==k) {
                v[j]=Ch[k*dimx+j]-alpha;
            } else {
                v[j]=Ch[k*dimx+j];
            }
            sigma+=(int32)v[j]*v[j];
        }
        
        alpha=sigma>>(qCh+1); // alpha = sigma /2;
        if (alpha==0) alpha =1;

        for (i=0;i<=k;i++) {
            sigma=0;
            for (j=0;j<dimx;j++) {
                sigma+=((int32)B[i*dimx+j]*w[j]);
            }
            for (j=0;j<=k;j++) {
                sigma+=(int32)Ch[i*dimx+j]*v[j];
            }

            sigma = sigma >> 15;               // navrat do Q15
          //  if (sigma>32767)sigma=32767;
			
            for (j=0;j<dimx;j++) 
            {
				tmp_long=B[i*dimx+j]-(sigma*w[j])/alpha;
				if (tmp_long>32767) {
					B[i*dimx+j]=32767;
				} else {
					if (tmp_long<-32767){
						B[i*dimx+j]=-32767;
					} else {
						B[i*dimx+j]=tmp_long;
					}
				}			
            };
            
            for (j=0;j<=k;j++)
            {
                tmp_long=Ch[i*dimx+j]-(sigma*v[j])/alpha;
				if (tmp_long>32767) {
					Ch[i*dimx+j]=32767;
				} else {
					if (tmp_long<-32767){
						Ch[i*dimx+j]=-32767;
					} else {
						Ch[i*dimx+j]=tmp_long;
					}
				}
			}
        }
    }

}

void carlson(int16 *difz, int16 *xp, int16 *Ch, int16 *R, unsigned int16 dimy, unsigned int16 dimx ) {
    int16 alpha,beta,gamma;
    int16 delta, eta,epsilon,zeta,sigma,tau;
    int16 i,j,iy;
    int16 w[5];
	int32 tmp_long;

    for (iy=0; iy<dimy; iy++)
    {
        alpha=R[iy];
        delta = difz[iy];

        for (j=0;j<dimx;j++)
        {
            sigma=Ch[iy*dimx+j];
            beta=alpha;
            alpha+=((int32)sigma*sigma)>>15;
//			double ab=(double)alpha*beta/32768./32768.;
//			double s_ab=sqrt(ab);
            gamma=(int16)(sqrt((double)((int32)alpha*beta))+0.5);            // predelat v DSP
            //gamma = round(s_ab*(1<<15));
//            eta=((long)beta<<15) / gamma;
            //zeta=(long(sigma)<<15)/ gamma;
            w[j]=0;
            for (i=0;i<=j;i++) {
                tau=Ch[i*dimx+j];
				tmp_long=((int32)beta*Ch[i*dimx+j] -(int32)sigma*w[i])/gamma;
		/*		if (tmp_long>32767) {
					Ch[i*dimx+j]=32767;
				} else {
					if (tmp_long<-32767){
						Ch[i*dimx+j]=-32767;
					} else {
		*/				Ch[i*dimx+j]=tmp_long;
			/*		}
				}
			*/	
                w[i]+=((int32)tau*sigma)>>15;
            }
        }

        //epsilon=(long(difz)<<15) / (alpha); // q15*q13/q13 = q15
        for (i=0;i<dimx;i++) {
            xp[i]+=((int32)w[i]*delta)/alpha;
        }
    }
}

/* perform Householder update of Ch matrix using PSI*Ch , Q, */
extern void givens(int16 *Ch /*= int16 *PSICh*/, int16 *Q, unsigned int16 dimx){
	int16 i,j,k;
	int16 rho,s,c,tau;
	int32  tmp_long;

	int16 A[25];//beware
	// copy Q to A
	for (i=0;i<dimx*dimx;i++) {
		A[i]=Q[i]>>(15-qCh);
	}


	for (i=dimx-1; i>=0; i--){
		for (j=0; j<dimx; j++) {
			tmp_long=(int32)Ch[i*dimx+i]*Ch[i*dimx+i]+int32(A[i*dimx+j])*A[i*dimx+j];
			if (tmp_long>0){
				rho=sqrt(double(tmp_long));
				s=(int32(A[i*dimx+j])<<15)/rho;
				c=(int32(Ch[i*dimx+i])<<15)/rho;
				for (k=0;k<=i; k++){
					tau=(int32(c)*A[k*dimx+j]-int32(s)*Ch[k*dimx+i])>>15;
					Ch[k*dimx +i]=(int32(s)*A[k*dimx+j]+int32(c)*Ch[k*dimx+i])>>15;
					A[k*dimx +j]=tau;
				}
			}
		}

		for (j=0; j<i; j++){
			tmp_long=(int32(Ch[i*dimx+i])*Ch[i*dimx+i]+int32(Ch[i*dimx+j])*Ch[i*dimx+j]);
			if (tmp_long>0){
				rho=sqrt((double)(tmp_long));
				s=(int32(Ch[i*dimx+j])<<15)/rho;
				c=(int32(Ch[i*dimx+i])<<15)/rho;
				for (k=0; k<=i; k++){
					tau=(int32(c)*Ch[k*dimx+j]-int32(s)*Ch[k*dimx+i])>>15;
					Ch[k*dimx+i]=(int32(s)*Ch[k*dimx+j]+int32(c)*Ch[k*dimx+i])>>15;
					Ch[k*dimx+j]=tau;
				}
			}
		}

	}
}

/* Matrix multiply Full matrix by upper diagonal matrix; */
void mmultACh(int16 *m1, int16 *up, int16 *result, unsigned int16 rows, unsigned int16 columns) {
	unsigned int16 i, j, k;
	int32 tmp_sum=0L;
	int16 *m2pom;
	int16 *m1pom=m1;
	int16 *respom=result;
	
	for (i=0; i<rows; i++) //rows of result
    {
		for (j=0; j<columns; j++) //columns of result
        {
			m2pom=up+j;//??
			
			for (k=0; k<=j; k++) //inner loop up to "j" - U(j,j)==1;
            {
				tmp_sum+=(int32)(*(m1pom++))**m2pom;
				m2pom+=columns;
			}
			m1pom-=(j+1); // shift back to first element
	
		/*	if (tmp_sum>(1<<29)-1) 
				*respom++=(1<<14);
			else
		*/	
		*respom++=(tmp_sum+(1<<14))>>15;
		
			tmp_sum=0;
		}
		m1pom+=(columns);
	}
}


void givens_fast(int16 *Ch, int16 *Q, unsigned int16 dimx)
{
	int16 i,j,k;
	int16 rho,s,c,tau;
	int32  tmp_long;
	
	//c,s in q14!!
	
	int16 A[25];//beware
	
	int16 *A_ij, *Q_i, *Ch_ki, *Ch_kj, *Ch_ii, *Ch_ij, *A_kj;
	
	A_ij=A;
	Q_i=Q;
	// copy Q to A
	for (i=0;i<dimx*dimx;i++)
	{
		//		A[i]=Q[i]>>(15-qCh);
		*A_ij++=(*Q_i++)>>(15-qCh);
	}
	
 	//printf("Gin: %d,%d,%d,%d\n", Ch[0],Ch[1],Ch[2],Ch[3] );
	
	for (i=dimx-1; i>=0; i--)
	{
		Ch_ii=Ch+i*dimx+i;
		A_ij=A+i*dimx;
		
		for (j=0; j<dimx; j++) 
		{
			if (*A_ij!=0)
			{
				tmp_long=(int32)*Ch_ii**Ch_ii+(int32)*A_ij**A_ij;
				//				rho=qsqrt(tmp_long);                   // verze pro DSP
				rho=(int16)(sqrt((double)tmp_long));     // verze pro PC
				s=(((int32)*A_ij)<<14)/rho;    // qCh + q14 /qch => s in q14
				c=(((int32)*Ch_ii)<<14)/rho;
				
				Ch_ki=Ch+i;
				A_kj=A+j;
				
				for (k=0;k<=i; k++)
				{
					tau=((int32)c**A_kj-(int32)s**Ch_ki)>>14; // tau in qCh
					tmp_long=(int32)s**A_kj+(int32)c**Ch_ki;  // q14+qCh
					if ((tmp_long>(1<<(14+14)))){ //q14 + q15
						*Ch_ki = (1<<14)-1; // rezerva pro nasobeni A*Ch
					}
					else 
						*Ch_ki=tmp_long>>14; // qCh
					*A_kj=tau;
					
					Ch_ki+=dimx;
					A_kj+=dimx;
				}
			}
			A_ij++;
		}
		
		Ch_ij = Ch+i*dimx;
		
		for (j=0; j<i; j++)
		{
			
			if (*Ch_ij>0)
			{
				tmp_long=(int32)*Ch_ii**Ch_ii+(int32)*Ch_ij**Ch_ij;
				//			rho=qsqrt(tmp_long);                     // verze pro DSP
				if (tmp_long>(1<<30)-1){
					rho=(1<<15)-1;
				}
				else
					rho=(int16)(sqrt((double)tmp_long));       // verze pro PC
						
				s=(((int32)*Ch_ij)<<14)/rho;
				c=(((int32)*Ch_ii)<<14)/rho;
				
				Ch_kj = Ch + j;
				Ch_ki = Ch + i;
				
				for (k=0; k<=i; k++)
				{
					tau=((int32)c**Ch_kj-(int32)s**Ch_ki)>>14;
					tmp_long =((int32)s**Ch_kj+(int32)c**Ch_ki);
					if ((tmp_long>(1<<(14+14)))){ //q14 + q15
						*Ch_ki = (1<<14)-1; // rezerva pronasobeni A*Ch
					}
					else 
						*Ch_ki=tmp_long>>14;
					*Ch_kj=tau;
					
					Ch_kj += dimx;
					Ch_ki += dimx;
				}
			}
			Ch_ij++;
		}
	}
}

void carlson_fast(int16 *difz, int16 *xp, int16 *Ch, int16 *R, unsigned int16 dimy, unsigned int16 dimx ) {
	int16 alpha,beta,gamma;
	int16 delta, eta,epsilon,zeta,sigma,tau;
	int16 i,j,iy;
	int16 w[5];
	int32 tmp_long;
	
	int16 *Ch_ij, *w_i, *x_i;
	
	
	for (iy=0; iy<dimy; iy++)
	{
		alpha=R[iy];
		delta = difz[iy];
		
		for (j=0;j<dimx;j++)
		{
			sigma=Ch[iy*dimx+j];
			beta=alpha;
			//            alpha+=((long)sigma*sigma)>>15;
			alpha=(((int32)alpha<<15)+(int32)sigma*sigma)>>15;				// vyssi presnost
			//            gamma= qsqrt(((long)alpha*beta));                          // verze pro DSP
			gamma= (int16)(sqrt((double)((int32)alpha*beta)));              // verze pro PC
			
			w[j]=0;
			
			Ch_ij=Ch+j;
			w_i=w;
			
			for (i=0;i<=j;i++)
			{
				//                tau=Ch[i*dimx+j];
				tau=*Ch_ij;
				//				tmp_long=((long)beta*Ch[i*dimx+j] -(long)sigma*w[i])/gamma;
				tmp_long=((int32)beta**Ch_ij -(int32)sigma**w_i)/gamma;
				
				if (tmp_long>32767){
					tmp_long=32767;
				}
				if (tmp_long<-32768)
					tmp_long=-32768;
				*Ch_ij=tmp_long;
				
				//                w_i+=((long)tau*sigma)>>15;
				*w_i=(((int32)*w_i<<15)+(int32)tau*sigma)>>15;
				
				w_i++;
				Ch_ij+=dimx;
			}
		}
		
		x_i=xp;
		w_i=w;
		for (i=0;i<dimx;i++) {
			//            xp[i]+=((long)w[i]*delta)/alpha;
			//            *x_i+=((long)*w_i*delta)/alpha;
			*x_i=((int32)*x_i*alpha+(int32)*w_i*delta)/alpha;		// vyssi presnost
			x_i++;
			w_i++;
		}
	}
}

void carlson_fastC(int16 *difz, int16 *xp, int16 *Ch, int16 *C, int16 *R, unsigned int16 dimy, unsigned int16 dimx, int16 *detS, int16 *rem ) {
	int16 alpha,beta,gamma;
	int16 delta, eta,epsilon,zeta,sigma,tau;
	int16 i,j,iy;
	int16 w[5];
	int32 tmp_long;
	
	int16 *Ch_ij, *w_i, *x_i, *C_yi;
	
	*detS = 32767;
	for (iy=0; iy<dimy; iy++)
	{
		alpha=R[iy];
		delta = difz[iy];
		
		for (j=0;j<dimx;j++)
		{
			C_yi = C+iy*dimx; 
			sigma = 0;
			Ch_ij=Ch+j;
			for (i=0;i<=j;i++){
				sigma += ((int32)*Ch_ij**C_yi)>>15; //sigma in qCh  
				Ch_ij+=dimx;
				C_yi++;
			}
			
			//sigma=Ch[iy*dimx+j];
			beta=alpha; // in q15
			//            alpha+=((long)sigma*sigma)>>15;
			tmp_long=((int32)alpha<<15)+(((int32)sigma*sigma)<<(30-2*qCh));
			alpha=(tmp_long+(1<<14))>>15;				// vyssi presnost
					
			//gamma= qsqrt(((long)alpha*beta));                          // verze pro DSP
			gamma= (int16)(sqrt((double)((int32)alpha*beta)));              // verze pro PC
			       // in q15
			w[j]=0;
			
			Ch_ij=Ch+j;
			w_i=w; // in q15
			
			for (i=0;i<=j;i++)
			{
				//                tau=Ch[i*dimx+j];
				tau=*Ch_ij;
				//				tmp_long=((long)beta*Ch[i*dimx+j] -(long)sigma*w[i])/gamma;
				tmp_long=((int32)beta**Ch_ij -(int32)sigma**w_i)/gamma; // in qCh
				
/*				if (tmp_long>32767)
					tmp_long=32767;
				if (tmp_long<-32768)
					tmp_long=-32768;*/
				*Ch_ij=tmp_long;
				
				//                w_i+=((long)tau*sigma)>>15;
				tmp_long = ((int32)*w_i<<15)+((int32)tau*sigma<<(30-2*qCh));
				*w_i=(tmp_long+(1<<14))>>15;
				
				w_i++;
				Ch_ij+=dimx;
			}
		}
		
		x_i=xp;
		w_i=w;
		for (i=0;i<dimx;i++) {
			//            xp[i]+=((long)w[i]*delta)/alpha;
			//            *x_i+=((long)*w_i*delta)/alpha;
			*x_i=((int32)*x_i*alpha+(int32)*w_i*delta)/alpha;		// vyssi presnost
			x_i++;
			w_i++;
		}
		
		*detS = ((int32)*detS*alpha+(1<<14))>>8;
		*rem += ((int32)delta*delta)/alpha;
	}
}

