针对问题三，为了对城市经济活力进行排名，首先要建立城市经济活力评价指标

For the three, in order to rank the city's economic vitality, we must first establish an evaluation system for economic vitality, by choosing capita GDP, per capita GDP growth rate of the total population, the total number of enterprises, investment in fixed assets, total foreign trade, the per capita disposable revenue, R & D expenditure as a percentage of GDP of the eight indicators completed the establishment of the system. Then factor analysis model to calculate the economic vitality of the city's 19 composite score of 19 cities were ranked scoring.

In order to rank the economic vitality of the city, the first step is to establish a system of evaluation indicators for the economic vitality of the city, by selecting per capita GDP, GDP growth per capita, total population, total number of enterprises, fixed asset investment, total foreign trade imports and exports, per capita disposable income, R . D funds as a percentage of GDP these eight indicators completed the establishment of the system. Then, using factor analysis model, the combined score of economic vitality of 19 cities was calculated, and 19 cities were ranked.

To solve the third problem, in order to rank the urban economic vitality, the first step is to establish the evaluation index system of urban economic vitality, which is completed by selecting eight indexes: per capita GDP, per capita GDP growth, total population, total number of enterprises, fixed asset investment, total amount of foreign trade import and export, per capita disposable income, and the proportion of R & D funds in GDP. Then factor analysis model is used to calculate the comprehensive scores of economic vitality of 19 cities and rank the scores of 19 cities.<br>