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From |
"Vasilis.Sarafidis" <[email protected]> |

To |
[email protected] |

Subject |
Re: st: clustering analysis |

Date |
07 Dec 2005 00:14:13 +0000 |

Sergio,

This appears to do the job! Thank you very much for your help!

Vasilis

On Dec 6 2005, Sergio Correia wrote:

the cluster commands uses a "randomized start". So you just need to write this set seed 123456 before each cluster kmeans..

Eg:

sysuse auto

set seed 123456

cluster kmeans price, k(2)

set seed 123456

cluster kmeans price, k(2)

set seed 123456

cluster kmeans price, k(2)

list _*

You will see they all belong to the same group

Sergio

On 06 Dec 2005 17:31:35 +0000, Vasilis.Sarafidis <[email protected]> wrote:

Statalist,

I am using the command "cluster kmeans" in order to cluster a sample of

objects on the basis of predefined attributes.

The thing is that everytime I run the command, the identity of the clusters changes, although the allocation of the objects is always the same. In other words, if there are 2 clusters only, then the first cluster takes one time the value of 1 and another time the value of 2. And vice versa for cluster 2.

The problem is that in my case I want to simulate some attributes and check how well does the clustering command do (on average) in allocating the objects into the correct clusters.

Notice that all the objects are ordered, in the sense that the first N/2

objects (that belong to the first cluster) are entered first.

Is there any way I can tell the program to make the identity of the first

cluster always equal to 1 and the identity of the second cluster equal to

2? Then in each replication I can easily find out whether the

cross-sections have been allocated in the correct cluster.

Many thanks for your help.

Vasilis

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**References**:**Re: st: clustering analysis***From:*Sergio Correia <[email protected]>

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