NAME: 　　udifference_test PURPOSE: Perform the difference test for two pairs of time-series data sets and test the fit of a normal distribution by χ-square test If both data sets obey the normal distribution, the Welch test is applied. If both data sets do not obey the normal distribution, only the Mann-Whitney test is used. SYNTAX: difference_test,vname1,vname2,sl=sl,test_sel=test_sel KEYWORDS: result:Test result. The values '0' and '1' mean that the judgement of the Welch test is different and same, respectively. Moreover, the values '2' and '3' mean that the judgement of the Mann-Whitney test is different and same, respectively. sl:Significant level. The default is 0.05. test_sel：Specify the test to be performed. The value '2' is the Mann-Whitney test, '1' is the Welch test, and '0' is to test the fit of a normal distribution by χ-square test CODE: R. Hamaguchi, 13/02/2012. MODIFICATIONS: A. Shinbori, 01/05/2013. A. Shinbori, 10/07/2013. ACKNOWLEDGEMENT: $LastChangedBy: jimm $ $LastChangedDate: 2014-02-11 10:52:58 -0800 (Tue, 11 Feb 2014) $ $LastChangedRevision: 14325 $ $URL $