CWT map for the monthly binned (upper) and the weekly binned light curve (bottom) for 4C +01.02 (left). In each subplot, the panels represent (a) Fermi-LAT light curve, (b) wavelet power spectrum and (c) global wavelet power spectrum. The solid coloured contours in (b) and the dashed coloured lines in (c) are the confidence levels (1 to 5σ in black, blue, green, violet, and red). Monthly binned and weekly binned light curves with the fitted periodic signal in red dashed lines in the upper panels and the relative error in the bottom panels (right).