Comparison of different methods of measuring the length of the bar, as a function of time (see the colour bar) for the fiducial bar model. For details of the bar measurement methods, see Sect. 3. In each case, a straight line of the form Y = AX + B is fitted (black dashed line) and the corresponding best-fit parameters are quoted in each sub-panel. In addition, in each case, the Pearson correlation is computed, and they are quoted in each sub-panel (see top left). The grey dotted line in each sub-panel denotes the one-to-one correspondence.