Improvement of the grey clustering method and its application in water quality assessment

Based on the principle of grey clustering analysis, an improved grey clustering method is given by adopting exponential whitening coefficient function and improving the method of establishing whitening function and the weights. With the improved method, the zero weight problem is addressed, the effects of exceeding standard factors are properly considered and the limitation, with which the classical method may lead some characteristic indicators have unreasonable weights as the clustering indicators have different means and dimensions, is effectively overcome, especially when they are quite different from each other quantitatively. Finally, an illustrative example is given to clarify the method, which shows that the improved method is reasonable, feasible, simple and practical.