Detection results for a GOES soft X-ray flare without evident quasiperiodic pulsations (QPPs). (a) Observed 1–8 Å light curve showing a typical flare profile without clear oscillatory signatures. (b) FFT+MCMC: the Fourier spectrum does not exhibit distinct periodic components. (c) CWT+AR(1): no statistically significant oscillatory power is detected, indicating that the method does not produce false positives in this case. (d) CWT+MCMC (this work): no statistically significant oscillatory power is detected, demonstrating robustness under nonstationary flare conditions. The 95% confidence level is indicated by contour lines.