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Table 1 Time complexity using O-Notation

From: Removing duplicated geometries in IFC models using rigid body transformation estimation and flyweight design pattern

Subroutine

Complexity

1) Semantical grouping

 

O(N p (N i  +  log N i )

  By type

O(1)

 

  By property

O(N i  + log N i )

 

2) Geometric comparison

 

\( O\left({N}_p^2{N}^2\right) \)

  Topological comparison

O(N log N)

 

  Compare underlying point sets

O(N2)

 

  Removing scale and translation

O(N)

 

  Create H = Q*Q’

O(N2)

 

  Singular value decomposition

O(1)

 

  Point comparison p’ = M*p

O(N) or O(N2)

 

3) Share identified duplicates

 

O(N p N2)

  Assign representation

O(1)

 

  Pre-multiply transformation

O(N2)

 

 

O(N p (N i  log N i  + N p N2))