Interactively modify map parallels
parallelui toggles the parallel tool on and off.
parallelui on activates the parallel tool
parallelui off deactivates the parallel tool
The parallelui GUI provides a tool to modify the standard parallels of a displayed map projection. One or two red lines are displayed where the standard parallels are currently located. The parallel lines can be dragged to new locations, and the map reprojected with the locations of the parallel lines as the new standard parallels.
A single-click-and-drag moves the parallel lines. A double-click on one of the standard parallels reprojects the map using the new parallel locations.