Dr. Gabriel Robins' BI1S Code

Contents

I.  Introduction 
II.  Data Formats
III.  Executable Utilities
IV.  References
V.  Contact


I. Introduction

This slot is focused on Batched Iterative 1-Steiner (BI1S) heuristic, which solves the Rectilinear Steiner Minimum Tree (RSMT) problem efficiently.
The idea of BI1S is to find in each iteration a Steiner point which can gain the largest wirelength saving if it is included in the pointset and a Minimum Spanning Tree (MST) is constructed over this pointset.
This code is a new and fast implementation which updates the MST in linear time (by updating only the nearest neighbors in four diagonal partitions) when inserting a Steiner point.


II. Data Formats

The program computes the MST cost and Steiner tree cost under 3 kind of modes: 1) Random pointsets, 2) Read in pointset, or 3) Automatic runs.
If 1) is chosen, the program prompts for the number of points, the number of iterations, the grid size, and a random seed. Each pointset of a given size is generated with a uniformed distribution over the grid size, and the MST cost and the Steiner tree cost for the pointset are computed and visualized in an X window.
If 2) is chosen, the program prompts for the number of points,the grid size, and the x/y coordinate of each point. A sample input of 4 points is as follows:
1 4
3 6
5 8
8 10
If 3) is chosen, the program prompts for the number of iterations and a random seed. The program then automatically generates pointsets of increasing size (from 3 to 50) over a wide range of grid sizes (from 10 to 10000).


III. Executable Utilities

(zipped code package)
(src code dir)

IV. References

  1. T. Barrera, J. Griffith, G. Robins and T. Zhang, Narrowing the Gap: Near-optimal Steiner Trees in Polynomial Time, Proc. IEEE International ASIC Conference, Rochester, NY, September 1993, pp. 87-90.
  2. T. Barrera, J. Griffith, S. A. Mckee, G. Robins and T. Zhang, Toward a Steiner Engine: Enhanced Serial and Parallel Implementations of the Iterated 1-Steiner Algorithm, Proc. Great Lakes Symposium on VLSI, Kalamazoo, MI, March 1993, pp. 90-94.
  3. J. Griffith, G. Robins, J. S. Salowe and T. Zhang, Closing the Gap: Near-Optimal Steiner Trees in Polynomial Time (.ps), (.pdf), IEEE Transactions on Computer-Aided Design, Vol. 13, No. 11, November 1994, pp. 1351-1365.
  4. Kahng, A. B., and Robins, G., A New Class of Iterative Steiner Tree Heuristics With Good Performance, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, Vol. 11, No. 7, July 1992, pp. 893-902.
  5. Kahng, A. B., and Robins, G., A New Family of Steiner Tree Heuristics with Good Performance: The Iterated 1-Steiner Approach, Distinguished Paper, Proc. IEEE International Conference on Computer-Aided Design, November 1990, pp. 428-431.

V. Contact

Dr. Gabriel Robins