高铁梅的《计量经济分析方法与建模--》第二版中的问题！！急！
第13章，主成份分析与因子分析中，第二个实例和第三个实例用principal factors得出的结论，怎么和书上得出的结论不一样啊？
以下是我的处理结果-----
Factor Method: Principal Factors     
Date: 10/13/09   Time: 12:23     
Covariance Analysis: Ordinary Correlation     
Sample: 1 100     
Included observations: 100     
Number of factors: User-specified     
Prior communalities: Squared multiple correlation     
     
Unrotated Loadings   
F1 F2 Communality Uniqueness
ALLIED -0.190964  0.467291  0.254828  0.745172
DUPONT -0.540627  0.468268  0.511553  0.488447
UNION -0.232761  0.476314  0.281053  0.718947
EXXON  0.502306  0.407821  0.418630  0.581370
TEXACO  0.603958  0.411304  0.533937  0.466063
     
Factor Variance Cumulative Difference Proportion Cumulative
F1  1.000000  1.000000  0.000000  0.500000  0.500000
F2  1.000000  2.000000 ---  0.500000  1.000000
Total  2.000000  3.000000   1.000000
     
Model Independence Saturated  
Discrepancy  1.116767  2.213602  0.000000  
Parameters  14  5  15  
Degrees-of-freedom  1  10 ---