YANG ET AL:ARE SLICE-BASED COHESION METRICS ACTUALLY USEFUL IN EFFORT-AWARE POST-RELEASE FAULT-PRONENESS... 345 TABLE 8 Results of Principal Component Analysis Sys. PC Eigen value %Var.%Cum Var Clustered metrics Bash 3.0 PCI 8160 0.302 0.302 SLOC FANOUT Cyclomatic CyclomaticModified CyclomaticStrict n1 n2 +N1+N2 PC2 6.201 0.230 0.532 Coverage+MinCoverage+Overlap+Tightness +WFC+SBFC PC3 3.397 0.126 0.658 Essential Knots+MaxEssentialKnots MinEssentialKnots PC4 1.078 0.040 0.698 Modified PC5 1.008 0.037 0.735 FANIN PC6 1.007 0.037 0.772 Deleted PC7 1.005 0.037 0.809 Added PC8 0.998 0.037 0.846 NPATH PC9 0.767 0.028 0.875 MaxCoverage P℃100.669 0.025 0.900 Nesting PC11 0.590 0.022 0.92 NHD Gcc-core 3.4.0 PC1 7.990 0.296 0.296 SLOC+Cyclomatic+CyclomaticModified +CyclomaticStrict+Essential+n2+NI +N2 PC2 5.790 0.214 0.510 Coverage MinCoverage+Overlap Tightness WFC+SBFC PC3 3.418 0.127 0.637 Knots MaxEssentialKnots MinEssentialKnots PC4 1.012 0.037 0.674 Modified PC5 1.007 0.037 0.712 Added PC6 1.002 0.037 0.749 Deleted PC7 0.993 0.0370.786 MaxCoverage PC8 0.989 0.0370.822 FANIN PC9 0.898 0.033 0.856 NPATH P℃10 0.869 0.032 0.888 Nesting PC11 0.677 0.025 0.913 NHD P℃12 0.557 0.021 0.933 nl PC13 0.547 0.020 0.954 FANOUT Gimp 2.0.0 PC1 6.239 0.231 0.231 SLOC Cyclomatic +CyclomaticModified CyclomaticStrict Nesting +nl N1 N2 PC2 5.004 0.1850.416 Coverage MinCoverage Overlap Tightness +SBFC PC3 3.068 0.1140.530 Knots MaxEssentialKnots MinEssentialKnots PC4 1.879 0.0700.600 MaxCoverage WFC PC5 1.704 0.0630.663 Modified PC6 1.604 0.059 0.722 FANOUT n2 PC7 1.014 0.038 0.760 NPATH PC8 1.008 0.037 0.797 FANIN PC9 1.003 0.03 0.834 Added PC10 1.001 0.037 0.871 Deleted P℃110.547 0.020 0.892 NHD PC12 0.486 0.0180.910 Essential Subversion 1.2.0 PC1 8.179 0.303 0.303 SLOC+FANOUT+Cyclomatic+CyclomaticModified CyclomaticStrict Essential +n2+N1+N2 PC2 4.674 0.1730.476 MinCoverage +Overlap Tightness +SBFC PC3 3.064 0.1130.590 Knots MaxEssentialKnots MinEssentialKnots PC4 2.570 0.095 0.685 Coverage MaxCoverage +WFC PC5 1.007 0.037 0.722 Deleted PC6 1.006 0.037 0.759 NPATH PC7 1.005 0.037 0.797 Added PC8 1.005 0.037 0.834 Modified PC9 1.001 0.037 0.871 FANIN PC100.616 0.0230.894 nl PC110.521 0.0190.913 Nesting P℃120.376 0.0140.927 NHD Vim 6.2 PC1 9.253 0343 0.343 SLOC FANOUT+NPATH+Cyclomatic CyclomaticModified CyclomaticStrict +Essential nl n2+N1 +N2 PC2 6.037 0.224 0.566 Coverage+MinCoverage +Overlap Tightness +WFC+SBFC PC3 3.295 0.122 0.688 Knots MaxEssentialKnots MinEssentialKnots PC4 1.031 0.038 0.727 Modified PC5 1.016 0.038 0.764 Nesting PC6 1.013 0.038 0.802 Added PC7 1.000 0.037 0.839 Deleted PC8 0.978 0.0360.875 FANIN PC9 0.906 0.0340.909 MaxCoverage PC100.587 0.0220.930 NHDTABLE 8 Results of Principal Component Analysis Sys. PC Eigen value %Var. %Cum Var. Clustered metrics Bash 3.0 PC1 8.160 0.302 0.302 SLOC þ FANOUT þ Cyclomatic þ CyclomaticModified þ CyclomaticStrict þ n1 þ n2 þ N1þ N2 PC2 6.201 0.230 0.532 Coverage þ MinCoverage þ Overlapþ Tightness þ WFC þ SBFC p PC3 3.397 0.126 0.658 Essential þ Knots þ MaxEssentialKnots þ MinEssentialKnots PC4 1.078 0.040 0.698 Modified PC5 1.008 0.037 0.735 FANIN PC6 1.007 0.037 0.772 Deleted PC7 1.005 0.037 0.809 Added PC8 0.998 0.037 0.846 NPATH PC9 0.767 0.028 0.875 MaxCoverage p PC10 0.669 0.025 0.900 Nesting PC11 0.590 0.022 0.921 NHD p Gcc-core 3.4.0 PC1 7.990 0.296 0.296 SLOC þ Cyclomatic þ CyclomaticModified þ CyclomaticStrict þ Essential þ n2 þ N1 þ N2 PC2 5.790 0.214 0.510 Coverage þ MinCoverage þ Overlap þ Tightness þ WFC þ SBFC p PC3 3.418 0.127 0.637 Knots þ MaxEssentialKnots þ MinEssentialKnots PC4 1.012 0.037 0.674 Modified PC5 1.007 0.037 0.712 Added PC6 1.002 0.037 0.749 Deleted PC7 0.993 0.037 0.786 MaxCoverage p PC8 0.989 0.037 0.822 FANIN PC9 0.898 0.033 0.856 NPATH PC10 0.869 0.032 0.888 Nesting PC11 0.677 0.025 0.913 NHD p PC12 0.557 0.021 0.933 n1 PC13 0.547 0.020 0.954 FANOUT Gimp 2.0.0 PC1 6.239 0.231 0.231 SLOC þ Cyclomatic þ CyclomaticModified þ CyclomaticStrict þ Nesting þ n1 þ N1 þ N2 PC2 5.004 0.185 0.416 Coverage þ MinCoverage þ Overlap þ Tightness þ SBFC p PC3 3.068 0.114 0.530 Knots þ MaxEssentialKnots þ MinEssentialKnots PC4 1.879 0.070 0.600 MaxCoverage þ WFC p PC5 1.704 0.063 0.663 Modified PC6 1.604 0.059 0.722 FANOUT þ n2 PC7 1.014 0.038 0.760 NPATH PC8 1.008 0.037 0.797 FANIN PC9 1.003 0.037 0.834 Added PC10 1.001 0.037 0.871 Deleted PC11 0.547 0.020 0.892 NHD p PC12 0.486 0.018 0.910 Essential Subversion 1.2.0 PC1 8.179 0.303 0.303 SLOC þ FANOUT þ Cyclomatic þ CyclomaticModified þ CyclomaticStrict þ Essential þ n2 þ N1 þ N2 PC2 4.674 0.173 0.476 MinCoverage þ Overlap þ Tightness þ SBFC p PC3 3.064 0.113 0.590 Knots þ MaxEssentialKnots þ MinEssentialKnots PC4 2.570 0.095 0.685 Coverage þ MaxCoverage þ WFC p PC5 1.007 0.037 0.722 Deleted PC6 1.006 0.037 0.759 NPATH PC7 1.005 0.037 0.797 Added PC8 1.005 0.037 0.834 Modified PC9 1.001 0.037 0.871 FANIN PC10 0.616 0.023 0.894 n1 PC11 0.521 0.019 0.913 Nesting PC12 0.376 0.014 0.927 NHD p Vim 6.2 PC1 9.253 0.343 0.343 SLOC þ FANOUT þ NPATH þ Cyclomatic þ CyclomaticModified þ CyclomaticStrict þ Essential þ n1 þ n2 þ N1 þ N2 PC2 6.037 0.224 0.566 Coverage þ MinCoverage þ Overlap þ Tightness þ WFC þ SBFC p PC3 3.295 0.122 0.688 Knots þ MaxEssentialKnots þ MinEssentialKnots PC4 1.031 0.038 0.727 Modified PC5 1.016 0.038 0.764 Nesting PC6 1.013 0.038 0.802 Added PC7 1.000 0.037 0.839 Deleted PC8 0.978 0.036 0.875 FANIN PC9 0.906 0.034 0.909 MaxCoverage p PC10 0.587 0.022 0.930 NHD p YANG ET AL.: ARE SLICE-BASED COHESION METRICS ACTUALLY USEFUL IN EFFORT-AWARE POST-RELEASE FAULT-PRONENESS... 345