labeling - Expression for placement of label 'offset from point' by azimuth field using QGIS?

I need help making an expression for labelling points, such that the label is placed in one of the 8 quadrants (above point excluded), based on the azimuth field of the point.

For example, if the azimuth is from 338-23 degrees, place in quadrant 1, if the azimuth is from 24-69 degrees, place in quadrant 2, and so on.

Answer

You can databind the label Placement Quadrant with this expression structure:

CASE 
  WHEN azimuth < 23 OR azimuth > 338 THEN 
    1 
  WHEN azimuth > 24 AND azimuth < 69 THEN
    2
  ELSE 
    3 

END

You may also need an expression calculating a more appropriate offset depending on the azimuth.

Update:

The offset can databind to an expression like this:

CASE 
  WHEN azimuth < 23 OR azimuth > 338 THEN 
    '0,-1' 
  WHEN azimuth > 24 AND azimuth < 69 THEN
    '1,0'

  ELSE 
    '-1,0' 
END

Negative x-values moves label west. Negative y-values moves label north. So '0,-1' means an x,y offset in 0 for x and 1 up north. Pick the unit used as map units, if you not using lat-long coordinates.