Relationship between P_cyc, both observed (see Fig. 1) and computed (diamonds), and P_rot for the stars of our sample. P_cyc has been computed with the one-dimensional dynamo model with a constant radial rotation profile and a assuming that the width of the tachocline varies with the rotation as explained in the text. Colours and symbols are as in Fig. 1. The fit plotted in black corresponds to the observed relationship presented in Fig. 1 and the fit in red to the one obtained with the computed cycles (the Sun excluded) with $P_{\text{cyc}}\left(\text{comp}\right)\propto P_{\text{rot}}^{1.22}$.