This example uses artificial data containing two clusters. One cluster is from a circular bivariate normal distribution. The other is a ring-shaped cluster that completely surrounds the first cluster. Without significance tests, the ring is divided into several sample clusters for any degree of smoothing that yields reasonable density estimates. The JOIN= option puts the ring back together. Output 78.3.1 displays a short summary generated from the first PROC MODECLUS statement. Output 78.3.2 contains a series of tables produced from the second PROC MODECLUS statement. The lack of p-value in the JOIN= option makes joining continue until only one cluster remains (see the description of the JOIN= option). The cluster memberships are then plotted as displayed in Output 78.3.1 through Output 78.3.8.

The following statements produce Output 78.3.1 through Output 78.3.8:

title 'Modeclus Analysis with the JOIN= option'; title2 'A Normal Cluster Surrounded by a Ring Cluster'; data circle; keep x y; c=1; do n=1 to 30; x=rannor(5); y=rannor(5); output; end; c=2; do n=1 to 300; x=rannor(5); y=rannor(5); z=rannor(5)+8; l=z/sqrt(x**2+y**2); x=x*l; y=y*l; output; end; run;

proc modeclus data=circle m=1 r=1 to 3.5 by .25 join=20 short; run;

proc modeclus data=circle m=1 r=2.5 join out=out; run;

proc sgplot data=out noautolegend; yaxis values=(-10 to 10 by 5); xaxis values=(-15 to 15 by 5); scatter y=y x=x / group=cluster Markerchar=cluster; by _NJOIN_; run;

Output 78.3.1: Significance Tests with the JOIN=20 and SHORT Options

Modeclus Analysis with the JOIN= option |

A Normal Cluster Surrounded by a Ring Cluster |

The MODECLUS Procedure

Cluster Summary | ||||
---|---|---|---|---|

R | Number of Clusters Joined |
Maximum P-value |
Number of Clusters |
Frequency of Unclassified Objects |

1 | 36 | 0.9339 | 1 | 301 |

1.25 | 20 | 0.7131 | 1 | 301 |

1.5 | 10 | 0.3296 | 1 | 300 |

1.75 | 5 | 0.1990 | 2 | 0 |

2 | 5 | 0.0683 | 2 | 0 |

2.25 | 3 | 0.0504 | 2 | 0 |

2.5 | 4 | 0.0301 | 2 | 0 |

2.75 | 3 | 0.0585 | 2 | 0 |

3 | 5 | 0.0003 | 1 | 0 |

3.25 | 4 | 0.1923 | 2 | 0 |

3.5 | 4 | 0.0000 | 1 | 0 |

Output 78.3.2: Significance Tests with the JOIN Option

Modeclus Analysis with the JOIN= option |

A Normal Cluster Surrounded by a Ring Cluster |

The MODECLUS Procedure

R=2.5 METHOD=1

Cluster Statistics | -Saddle Test: Version 92.7- | ||||||||
---|---|---|---|---|---|---|---|---|---|

Cluster | Frequency | Maximum Estimated Density |
Boundary Frequency |
Estimated Saddle Density |
Mode Count |
Saddle Count |
Overlap Count |
Z | Approx P-value |

1 | 103 | 0.00617328 | 22 | 0.00308664 | 39 | 19 | 0 | 2.495 | 0.5055 |

2 | 71 | 0.00571029 | 20 | 0.0043213 | 36 | 27 | 9 | 1.193 | 0.999 |

3 | 53 | 0.00509296 | 18 | 0.00401263 | 32 | 25 | 10 | 0.986 | 0.9999 |

4 | 45 | 0.00478429 | 19 | 0.00354964 | 30 | 22 | 14 | 1.429 | 0.9924 |

5 | 30 | 0.00462996 | 0 | . | 29 | 0 | . | 3.611 | 0.0301 |

6 | 28 | 0.00370397 | 17 | 0.00354964 | 23 | 22 | 9 | 0.000 | 1 |

Cluster 6 with P-value 1.0000 will be joined to cluster 4. |

Cluster Statistics | -Saddle Test: Version 92.7- | ||||||||
---|---|---|---|---|---|---|---|---|---|

Cluster | Frequency | Maximum Estimated Density |
Boundary Frequency |
Estimated Saddle Density |
Mode Count |
Saddle Count |
Overlap Count |
Z | Approx P-value |

1 | 103 | 0.00617328 | 22 | 0.00308664 | 39 | 19 | 0 | 2.495 | 0.5055 |

2 | 71 | 0.00571029 | 20 | 0.0043213 | 36 | 27 | 9 | 1.193 | 0.999 |

3 | 53 | 0.00509296 | 18 | 0.00401263 | 32 | 25 | 10 | 0.986 | 0.9999 |

4 | 73 | 0.00478429 | 13 | 0.00293231 | 30 | 18 | 0 | 1.588 | 0.9778 |

5 | 30 | 0.00462996 | 0 | . | 29 | 0 | . | 3.611 | 0.0301 |

Cluster 3 with P-value 0.9999 will be joined to cluster 1. |

Cluster Statistics | -Saddle Test: Version 92.7- | ||||||||
---|---|---|---|---|---|---|---|---|---|

Cluster | Frequency | Maximum Estimated Density |
Boundary Frequency |
Estimated Saddle Density |
Mode Count |
Saddle Count |
Overlap Count |
Z | Approx P-value |

1 | 156 | 0.00617328 | 17 | 0.00246931 | 39 | 15 | 0 | 3.130 | 0.1318 |

2 | 71 | 0.00571029 | 20 | 0.0043213 | 36 | 27 | 9 | 1.193 | 0.999 |

3 | 73 | 0.00478429 | 13 | 0.00293231 | 30 | 18 | 0 | 1.588 | 0.9778 |

4 | 30 | 0.00462996 | 0 | . | 29 | 0 | . | 3.611 | 0.0301 |

Cluster 2 with P-value 0.9990 will be joined to cluster 3. |

Cluster Statistics | -Saddle Test: Version 92.7- | ||||||||
---|---|---|---|---|---|---|---|---|---|

Cluster | Frequency | Maximum Estimated Density |
Boundary Frequency |
Estimated Saddle Density |
Mode Count |
Saddle Count |
Overlap Count |
Z | Approx P-value |

1 | 156 | 0.00617328 | 17 | 0.00246931 | 39 | 15 | 0 | 3.130 | 0.1318 |

2 | 144 | 0.00571029 | 14 | 0.00293231 | 36 | 18 | 0 | 2.313 | 0.6447 |

3 | 30 | 0.00462996 | 0 | . | 29 | 0 | . | 3.611 | 0.0301 |

Cluster 2 with P-value 0.6447 will be joined to cluster 1. |

Cluster Statistics | -Saddle Test: Version 92.7- | ||||||||
---|---|---|---|---|---|---|---|---|---|

Cluster | Frequency | Maximum Estimated Density |
Boundary Frequency |
Estimated Saddle Density |
Mode Count |
Saddle Count |
Overlap Count |
Z | Approx P-value |

1 | 300 | 0.00617328 | 0 | . | 39 | 0 | . | 4.246 | 0.0026 |

2 | 30 | 0.00462996 | 0 | . | 29 | 0 | . | 3.611 | 0.0301 |

30 observations were unassigned. |

Cluster 1 with P-value 0.0026 will be dissolved. |

Modeclus Analysis with the JOIN= option |

A Normal Cluster Surrounded by a Ring Cluster |

The MODECLUS Procedure

Cluster Summary | ||||
---|---|---|---|---|

R | Number of Clusters Joined |
Maximum P-value |
Number of Clusters |
Frequency of Unclassified Objects |

2.5 | 0 | 1.0000 | 6 | 0 |

2.5 | 1 | 0.9999 | 5 | 0 |

2.5 | 2 | 0.9990 | 4 | 0 |

2.5 | 3 | 0.6447 | 3 | 0 |

2.5 | 4 | 0.0301 | 2 | 0 |

2.5 | 5 | 0.0026 | 1 | 30 |

Output 78.3.3: Cluster Memberships When Number of Clusters Joined=0

Output 78.3.4: Cluster Memberships When Number of Clusters Joined=1

Output 78.3.5: Cluster Memberships When Number of Clusters Joined=2

Output 78.3.6: Cluster Memberships When Number of Clusters Joined=3

Output 78.3.7: Cluster Memberships When Number of Clusters Joined=4

Output 78.3.8: Cluster Memberships When Number of Clusters Joined=5