python - QGIS Field Pyculator Reclass

I'm new to the QGIS Pyculator and need to reclass a field ('AP') based on another field ('Mag'). What I have so far, from the ArcGIS field calculator:

def Reclass(Mag,AP):
    if Mag>= 2000:
        return "M"
    elif Mag>80 and Vector_Mag<2000:
        return "L"
    elif Mag<=80 :
        return "S"

    else:
        return "UNCLASS"

With the expression as:

Reclass(!Mag!,!AP!)

How does this translate into the QGIS Field Pyculator?

Answer

In the FieldPyculator, you will need to:

• Insert your function as a Global expression and remove the AP parameter as you can choose from the GUI which field you want updated.


• Slightly change your Field expression by specifying fields using instead of !Mag!.

---

This is the global expression I used (not sure what Vector_Mag was so changed these to Mag):

def Reclass(Mag):
    if Mag >= 2000:
        return "M"
    elif Mag > 80 and Mag < 2000:
        return "L"

    elif Mag <= 80:
        return "S"
    else:
        return "UNCLASS"

This is the field expression:

value = Reclass()