matlab编程，实现灰色预测模型,基于当前已有的数据，用来预测未来一段时间内的发展趋势，对于线性发展趋势拟合情况很好，对于非线性预测差一点。-matlab programming, gray prediction model based on the current available data to predict future trends over time, the linear trends fit in good condition, almost nonlinear prediction.