"""
Define new functions using @qgsfunction. feature and parent must always be the
last args. Use args=-1 to pass a list of values as arguments
"""

from qgis.core import *
from qgis.gui import *
 
@qgsfunction(args='auto', group='Custom')
def azimuth(x1,y1,x2,y2, feature, parent):
    p1 = QgsPoint(x1,y1)
    p2 = QgsPoint(x2,y2)
    a = p1.azimuth(p2)
    if a < 0:
 
        a += 360
    return a