There are 251 CSV files in the folder pict, and the file naming instructions are as follows:
   subject_generator_generation method_ n. CSV
   subject: Flex, Grep (SIR), Gzip, Make, Sed, NanoXML, Siena, Findutils, Grep (CoRE), Cp, Cut, Du, Expr, Ls, Rm, Seq, Tail;
   generator: pict, acts
   generation method: bot (bottom up), top (top down), hyb (hybrid);
   n: 1-5, indicating 5 measurements;
For example: Make_pict_bot_1. CSV
    There are two columns in each file, the first column is the number of test cases executed, and the second column is the corresponding number of code coverage lines.
