问题
Possible Duplicate:
How do I determine k when using k-means clustering?
How can we determine the value of K(the number of clusters) for the k-means algorithm ??
回答1:
Sometimes.
There are various methods, that usually require trying different values of k and measuring which worked best.
Here are some duplicate questions you missed:
How to optimal K in K - Means Algorithm
K-Means Algorithm
Kmeans without knowing the number of clusters?
K means finding elbow when the elbow plot is a smooth curve
来源：https://stackoverflow.com/questions/11360403/how-to-determine-the-k-value-for-k-means-algorithm