[GRASS-user] Smoothing unclosed contour

Hi list,

Help me please! I have a set of unclosed contours, which are created from raster cropped by the mask.
After smoothing with “v.generalize method=boyle look_ahead=5” I have obtained smooth, but duplicated contours.

How can I fix it? If it necessary I can send a screenshot.

Best regards, Dmitriy