39   planck_assert(nside_<orig.
nside_,
"Import_degrade: this is no degrade");
    40   int fact = orig.
nside_/nside_;
    41   planck_assert (orig.
nside_==nside_*fact,
    42     "the larger Nside must be a multiple of the smaller one");
    44   int minhits = pessimistic ? fact*fact : 1;
    48 #pragma omp for schedule (static)    49   for (m=0; m<npix_; ++m)
    54     kahan_adder<double> adder;
    55     for (
int j=fact*y; j<fact*(y+1); ++j)
    56       for (
int i=fact*x; i<fact*(x+1); ++i)
    58         int opix = orig.xyf2pix(i,j,f);
    62           adder.add(orig.map[opix]);
    65     map[m] = T((hits<minhits) ? 
Healpix_undef : adder.result()/hits);
    77   Min = T(1e30); Max = T(-1e30);
    78   for (
int m=0; m<npix_; ++m)
 void minmax(T &Min, T &Max) const
const double Healpix_undef
Healpix value representing "undefined". 
void Import_degrade(const Healpix_Map< T > &orig, bool pessimistic=false)