I noticed that tree agglomeration was not done correctly.
The previous method used drop.tip() with drop.internal option. This was problematic because of the following reason.
Nodes of rowTree represents rows. A row can be in internal node, it does not have to be in tip. Sometimes internal node does not belong to any other row (for instance child node of this kind of internal node could represent other row).
When drop.internal option is used, the whole branch corresponding to the tip being removed is dropped. It can be that we lose internal node representing specific row, if the internal node does not have any child nodes that are kept.
Now the pruning is done one tip-layer at the time to ensure that we keep all nodes that represent rows.
I noticed that tree agglomeration was not done correctly.
The previous method used
drop.tip()withdrop.internaloption. This was problematic because of the following reason.drop.internaloption is used, the whole branch corresponding to the tip being removed is dropped. It can be that we lose internal node representing specific row, if the internal node does not have any child nodes that are kept.Now the pruning is done one tip-layer at the time to ensure that we keep all nodes that represent rows.