Each row corresponds to one configuration. Left column: Moment 0 maps. Middle column: Moment 1 maps. The gas component has been inclined by i_true = 40° and rotated so the bar could form a 45° angle with respect to the galaxy kinematic axes. The image parameters and the isovelocity contours are the same as in Fig. 1. Right column: Corresponding bar diagram with the radial motion interpretation according to the gas velocity vector projected on the minor axis in red and the major axis in green.