@fengjie08, There is no code affter the trace and layout definition. The two lists, pl_hsv and pl_twilight are cyclic colorscale. pl_hsv is illustrated in my answer to the question posted by gislainp, above.
@fengjie08, There is no code affter the trace and layout definition. The two lists, pl_hsv and pl_twilight are cyclic colorscale. pl_hsv is illustrated in my answer to the question posted by gislainp, above.