数据如下:
- * Example generated by -dataex-. To install: ssc install dataex
- clear
- input int timeid float(dgbpusd daudusd deurusd)
- 1 . . .
- 2 -.0113 .0025 -.0091
- 3 -.0035 .0034 -.0083
- 4 -.0012 .0022 .004
- 5 -.0004 -.004 -.0013
- 6 .0046 -.0026 -.004
- 7 .0033 -.0001 .0032
- 8 .0002 .0095 .0062
- 9 -.01 .0059 .0001
- 10 .0057 -.0087 .0008
- 11 -.0069 -.0051 -.0074
- 12 -.0017 -.0095 .0015
- 13 .007 -.004 -.0079
- 14 .0005 .003 .0011
- 15 .0048 -.0005 .0009
- 16 .0098 .0046 -.0014
- 17 .0062 -.0084 .0149
- 18 -.0155 -.0085 -.0018
- 19 .0103 .0056 -.0005
- 20 -.0006 .004 -.0002
- 21 -.0016 -.004 -.0008
- 22 -.0078 .0055 -.0108
- 23 -.0046 -.0038 -.0069
- 24 -.0134 -.0003 .0039
- 25 .002 .0172 -.0006
- 26 -.0016 -.0015 .0014
- 27 .0013 .0049 .0057
- 28 .0089 0 .0045
- 29 -.0008 -.001 .0011
- 30 .0047 .0089 -.0008
- 31 .0146 -.0011 -.0045
- 32 .0063 -.0048 .0088
- 33 .0088 .0055 .0012
- 34 -.0033 -.0002 .0014
- 35 -.003 -.0005 .0052
- 36 -.0004 -.0027 -.0026
- 37 -.0029 .0007 -.0014
- 38 -.0035 -.003 .0027
- 39 .004 .0058 -.0011
- 40 .0025 -.0016 .001
- 41 -.001 -.0051 -.0058
- 42 .0017 -.0003 .0023
- 43 .0057 -.0041 .0092
- 44 -.0078 .0014 -.0067
- 45 -.0003 .0012 .0008
- 46 .0058 .0035 -.001
- 47 .0018 .0105 .0128
- 48 -.0027 -.0022 .0014
- 49 -.0068 -.0048 .0002
- 50 -.0028 -.0043 -.0017
- 51 .0002 .0011 .0043
- 52 .0005 .0043 -.0035
- 53 .0023 -.0003 .0046
- 54 -.001 .0059 .0008
- 55 -.0044 .004 .0012
- 56 -.0052 -.0085 -.0101
- 57 -.0037 -.0003 -.0054
- 58 -.0018 .0042 .0015
- 59 .0012 .0052 .0045
- 60 .0031 .0033 -.0013
- 61 .0054 .006 -.0045
- 62 .0028 .0033 -.0041
- 63 .0027 -.0012 .0012
- 64 .0024 .0017 .0017
- 65 -.0032 -.0017 .0024
- 66 -.0004 .0001 -.0026
- 67 -.0028 -.0016 -.0047
- 68 -.0023 .006 -.0015
- 69 .0033 -.0022 .0037
- 70 .0139 .009 .0055
- 71 .0046 .0031 .0058
- 72 -.0008 .0022 .0031
- 73 -.0052 -.0016 -.0001
- 74 -.0004 .0027 -.0064
- 75 .0001 -.0062 -.0006
- 76 .0067 .0009 .0001
- 77 -.0003 -.0041 -.0002
- 78 0 .0003 -.0001
- 79 -.0002 -.0005 -.002
- 80 .0032 .0039 .0012
- 81 -.0042 -.0076 .0012
- 82 .002 -.0027 .0014
- 83 .0001 .0017 .0003
- 84 .0004 -.0023 .0017
- 85 .002 .001 -.0039
- 86 .0046 .0019 .0055
- 87 .002 -.0013 .0003
- 88 -.0023 .0003 -.0001
- 89 -.0004 -.0003 .0006
- 90 .0109 .0077 .0053
- 91 -.0023 -.0024 -.0018
- 92 -.002 .0048 -.007
- 93 -.0081 -.0013 -.0082
- 94 .0017 0 -.0001
- 95 -.0042 -.0002 -.0053
- 96 -.0059 .0018 .0011
- 97 .0023 -.0022 -.0005
- 98 .0021 .0004 -.0016
- 99 .0003 -.003 .0015
- 100 .0024 -.0087 -.0007
- end
程序如下:
- foreach y of var dgbpusd daudusd deurusd {
- foreach x of var dgbpusd daudusd deurusd {
- if `y' != `x' {
- reg `y' `x', noheader
- }
- }
- }
既不报错,也不出回归结果。
而何其几乎一模一样的程序则可以运行,如下所示:
- sysuse auto, clear
- foreach y of var price mpg rep78 {
- foreach x of var price mpg rep78 {
- if `x' != `y' {
- reg `y' `x'
- }
- }
- }
求指教是什么原因!!!
多谢多谢!