<put algorithm description here>
<put parameter description here>
Default: NewField
<put parameter description here>
Options:
Default: 0
<put parameter description here>
Default: 10
<put parameter description here>
Default: 0
Optional.
<put parameter description here>
Default: (not set)
<put parameter description here>
Default: value =
processing.runalg('qgis:advancedpythonfieldcalculator', input_layer, field_name, field_type, field_length, field_precision, global, formula, output_layer)