Fig. 6. Graphs of relative lift L_r against _b for the unpaired (A—C) and paired (D—F) analyses of the angle series data, and against U (G—I) for the speed series data. The usual red/green/blue colour coding of the locusts applies. Horizontal black lines denote equilibrium levels of dimensionless force production. Vertical black lines denote the reference speed U_ref and body angle _b,ref. In each of A—F, the single data point at 7° represents the mean of the 14 measurements at _b,ref. Regression lines are only drawn if the slope of the individual regression was significant and if U or _b attained overall significance in the corresponding pooled general linear model. The error bars on the regressions for the unpaired analysis (A—C, G—I) show the 95% confidence interval for the regression mean (±1.96 S.E.M.). The error bars on the regressions for the paired analyses (D—F) show the 95% confidence interval for the mean of the 14 reference measurements (±1.96 S.E.M.), which in this case provides the only independent estimate of the height of the curve above the x-axis. The broken lines represent the 95% confidence interval for the slope of the regression plus the 95% confidence interval for the slope of the corrections for tunnel speed or balance orientation. Note that the combined confidence interval for the slope may include zero even if the P-value for the regression slope itself is significant.