def reduce_to_leaves(self, id=''):
"""
create a new set of rois which are only the leaves of self
"""
isleaf = Forest(self.k, self.parents).isleaf()
label = self.label.copy()
label[isleaf[self.label]==0] = -1
k = np.sum(isleaf.astype(np.int))
if self.k==0:
return HierarchicalROI(self.domain, label, np.array([]), id)
parents = np.arange(k)
nroi = HierarchicalROI(self.domain, label, parents, id)
# now copy the features
fids = self.features.keys()
for fid in fids:
df = [self.features[fid][k] for k in range(self.k) if isleaf[k]]
nroi.set_feature(fid, df)
return nroi
