插值拟合在国民经济增长预测中的应用

The Application of Interpolation Fitting in the Forecast of NationalEconomic GrowthAbstract This subject requires me to use interpolation model and fitting model to study andforecast the growth trend of national economy.In China's new national economic accountingsystem,GDP is an important indicator that can fully reflect and measure the developmenttrend of China's national economy.Therefore,I selected China 's GDP data from 2005 to2014 to build a model,and predicted China 's GDP from 2015 to 2019 through the model.This subject uses the following three mathematical models to study and predict China's GDP.namely Lagrange interpolation model,Newton interpolation model and polynomial curvefitting model.This subject choose three models implemented by MATLAB.Use MATLAB to makescatter plots based on known data and explore the growth trend of existing data.Accordingto the trend choose the appropriate function model.Then write MATLAB code throughlearning of theoretical knowledge.Find the prediction result through MATLAB.Finally,anerror analysis is performed on the three models.Error analysis is obtained by comparingactual values with predicted values.MATLAB can be used to generate fitting curves anderror graphs,and the accuracy and feasibility of the three models can be compared moreclearly through line graphs.It is very helpful for us to compare the pros and cons of the threemodelsAfter a series comparison,I found that the accuracy of the interpolated model is lowerthan that of fitting model.The numerical accuracy of the third-order polynomial curve fittingmodel is the highest among several models.Both the interpolation model and the fittingmodel should not excessively pursue higher orders when selecting the approximate function.Because the more data,the larger the order,the greater the error.Key words national economy GDP interpolation fitting model error analysisⅡ