/* A simple version of quicksort; taken from Kernighan and Ritchie, page 87 */
static PetscErrorCode PetscSortReal_Private(PetscReal *v,PetscInt right)
{
PetscInt i,last;
PetscReal vl,tmp;
PetscFunctionBegin;
if (right <= 1) {
if (right == 1) {
if (v[0] > v[1]) SWAP(v[0],v[1],tmp);
}
PetscFunctionReturn(0);
}
SWAP(v[0],v[right/2],tmp);
vl = v[0];
last = 0;
for (i=1; i<=right; i++) {
if (v[i] < vl) {last++; SWAP(v[last],v[i],tmp);}
}
SWAP(v[0],v[last],tmp);
PetscSortReal_Private(v,last-1);
PetscSortReal_Private(v+last+1,right-(last+1));
PetscFunctionReturn(0);
}
/*@
PetscSortReal - Sorts an array of doubles in place in increasing order.
Not Collective
Input Parameters:
+ n - number of values
- v - array of doubles
Level: intermediate
Concepts: sorting^doubles
.seealso: PetscSortInt(), PetscSortRealWithPermutation()
@*/
PetscErrorCode PetscSortReal(PetscInt n,PetscReal v[])
{
PetscInt j,k;
PetscReal tmp,vk;
PetscFunctionBegin;
if (n<8) {
for (k=0; k<n; k++) {
vk = v[k];
for (j=k+1; j<n; j++) {
if (vk > v[j]) {
SWAP(v[k],v[j],tmp);
vk = v[k];
}
}
}
} else PetscSortReal_Private(v,n-1);
PetscFunctionReturn(0);
}
