ConstCubeSlice<T>::ConstCubeSlice(const ConstCubeSlice<T>& bigger, long i,
long dOffset)
{
assert(dOffset >= 0 && dOffset <= bigger.getNumDims());
// allow zero-dimensional slice
assert(i >= 0 && i < bigger.getProd(0, dOffset));
data = bigger.data;
sig = bigger.sig;
dimOffset = dOffset + bigger.dimOffset;
sizeOffset = bigger.sizeOffset + i*bigger.getProd(dOffset);
}
void getHyperColumn(Vec<T>& v, const ConstCubeSlice<T>& s, long pos)
{
long m = s.getProd(1);
long n = s.getDim(0);
assert(pos >= 0 && pos < m);
v.SetLength(n);
for (long i = 0; i < n; i++)
v[i] = s[pos + i*m];
}