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??????????????????????????????(Metamorphic Testing)????壺

????Metamorphic testing is used in conjunction with other test case selection strategies Given a test case selection strategy S?? such as path coverage?? a set of test cases T ={t1??t2??t3...tn} ?? where is n>=1 generated. The program is then tested on T . If no failure is revealed after running all in T for i = 2?? .. . ?? n??then T will be a set of successful test cases.

????At this stage?? metamorphic testing can be carried out to generate follow-up test cases according to metamorphic relations. A metamorphic relation (MR) is an expected relation among the inputs and outputs of multiple executions of the target program. For a successful test case and a chosen MR?? we can construct follow-up test say ti?? and run the program again. Let p denote the program under test. We check ti?? p(ti)??ti?? and p(ti??)against the MR. If MR cannot be satisfied?? the program must have failed.

?????????????????????????Щ?????????????????????????????????????????????????????????????????????????metamorphic relation(MR)??????????????????????????????????????sin?????????(??????????)??????????????????????Щ?????????в????????sin(0)=0??sin(Pi/2)=1 ??????????????????????????????sin(2)????????0.909??????????????ж?????????????????????????￡????????????Щ?????MR????????????????????в????????sin(x)=-sin(-x)??sin(x)=sin(pi-x)(????MR)?????????κ?Υ?????????????????????????????????????д??????