int solve(FILE* fp){
int n = getsize(fp),i,j;
float *array = (float *) malloc (((n+1)*n)*sizeof(float));
float det = 1.0;
generate(array,n,fp);
int flag = 0;
for(j=0;j<n-1;j++){
int k=j,l;
float pivot=*(array+(n)*j+j);
if(abs(pivot)<=0.01){ //Swap if pivots get too small
flag += rowswap(array,j,n);
pivot=*(array+(n)*j+j);
}
for(l=k+1;l<n;l++){
float next=*(array+(n)*(l)+j)/pivot;
for(i=j;i<n+1;i++)
*(array+(n)*l+i)-=*(array+(n)*(k)+i)*next; }
}
for(i=0;i<n;i++){
float ii = *(array + n*i + i);
det *= ii;
}
for(i=0;i<flag;i++){
det*=-1;
}
printf("Determinant: %f\n",det);
free(array);
return 0;
}
void gauss(int i, int j)
{
printab();
if(i+1<rows && j+1<cols)
{
if(notnull(i,j)==rows)
gauss(i,j+1);
else
{
if(!tab[j+i*cols])
{
rowswap(i,notnull(i+1,j));
gauss(i,j);
}
else
if(notnull(i+1,j)!=rows)
{
rowdux(i,j,notnull(i+1,j));
gauss(i,j);
}
else
gauss(i+1,j+1);
}
}
}
bool Matrix3::setInverse(const Matrix3& a)
{
Matrix3 _a(a);
Matrix3& _b = *this;
_b.setIdentity();
int i,j,i1;
for(j=0;j<3;j++) {
i1 = j;
for(i=j+1;i<3;i++)
if (Abs(_a(i,j)) > Abs(_a(i1,j)))
i1 = i;
rowswap(_a,i1,j);
rowswap(_b,i1,j);
if (FuzzyZero(_a(j,j))){
fprintf(stderr, "Taking inverse of singular Matrix3\n");
return false;
}
register Real div = Inv(_a(j,j));
_b(j,0) *= div;
_b(j,1) *= div;
_b(j,2) *= div;
_a(j,0) *= div;
_a(j,1) *= div;
_a(j,2) *= div;
for(i=0;i<3;i++) {
if (i != j) {
register Real tmp = _a(i,j);
_b(i,0) -= tmp*_b(j,0);
_b(i,1) -= tmp*_b(j,1);
_b(i,2) -= tmp*_b(j,2);
_a(i,0) -= tmp*_a(j,0);
_a(i,1) -= tmp*_a(j,1);
_a(i,2) -= tmp*_a(j,2);
}
}
}
return true;
}
float uppertriag(float *array,int n){
int i,j;
for(j=0;j<n-1;j++){
int k=j,l;
float pivot1=*(array+(2*n)*j+j);
if(abs(pivot1)<=0.01){ //Swap if pivots get too small
rowswap(array,j,2*n);
pivot1=*(array+(2*n)*j+j);
}
for(l=k+1;l<n;l++){
float next=*(array+(2*n)*(l)+j)/pivot1;
for(i=j;i<2*n;i++)
*(array+(2*n)*l+i)-=*(array+(2*n*k)+i)*next;
}
}
return *(array + (2*n)*(n-1) + n-1);
}
