I’m looking to debug a strange hypothesis test result, with CLs=0. For the model, a completely free RooFitResult works fine, converges and has correct status flags (cov. quality, fit status, etc.). However, the HypoTestResults shows something interesting.
CLb() returns something non-zero, but CLsplusb() returns 0. As a consequence, CLs() returns zero as well. The reason is presumably that the signal is too strong, since an UL scan works fine and shows an UL ~ 0.6. For mu_SIG=0.98 (the last point the scan range picks up) the CLs value is 10^-6.
In order to figure out more about what happened, I’d like to use NullDetailedOutput() and AltDetailedOutput() to see more of the fits. I’m using a PLL test statistic, and have set this:
However, I still get 0x0 for both sets of detailed output. Lorenzo’s hypothesis test example also shows no additional lines, so I’m not entirely sure what I’m missing.
To get these numbers I’m using the asymptotic method (not toys), could that be causing this? Second, is there a robust way to help the hypotest for fixed mu_SIG=1 along so that it won’t return CLs=0? Lastly, is there an easy way to set the cutoff CLs value for the HypoTestInverter?