PYTHON Cross and Dot product function with logic with Directional Vector??

When posting Python code, can you please apply the Code Snippet formatting to make it more readable.

That said, why are you declaring a function "my_function" inside the input method, and then never calling it?

@david_r​ tnx for your reply, this is my first python code and am learning so not so much sure, how to get the code snippet formatting. I just copied and pasted from PythonCaller. However i have attached the FME workbench above.

You can use that button on a selected piece of text 

To create a code snippet

(and on a general note, a little bit more info in the title of your post would make it easier for people browsing the list of topics to see what it's about)

@Hans van der Maarel​ :) thank you some new learning today

Try the following (untested). Be careful to preserve indents. I'm assuming that the incoming attributes DX, DY and DZ are simple numbers (int or float), the code needs modification if that is not the case.

import fme
import fmeobjects
import numpy as np
 
class FeatureProcessor(object):
 
    def __init__(self):
        pass
 
    def input(self, feature):
        # Retrieve FME feature attributes into Python attributes
        L = feature.getAttribute('L')
        F = feature.getAttribute('F')
        DX = float(feature.getAttribute('DX'))
        DY = float(feature.getAttribute('DY'))
        DZ = float(feature.getAttribute('DZ'))
        
        # Call our function
        L, F, DX, DY, DZ, DU, DV, DN = myfunction(L, F, DX, DY, DZ)
        
        # Set FME feature attributes based on return values
        feature.setAttribute('L', L)
        feature.setAttribute('F', F)
        feature.setAttribute('DX', DX)
        feature.setAttribute('DY', DY)
        feature.setAttribute('DZ', DZ)
        feature.setAttribute('DU', DU)
        feature.setAttribute('DV', DV)
        feature.setAttribute('DN', DN)
        
        self.pyoutput(feature)
    
    def close(self):
        pass
 
def myfunction(L, F, DX, DY, DZ):
    DLF = [0,0,-1]
    ULF = [0,0,1]
    NLF = [0,1,0]
    SLF = [0,-1,0]
    ELF = [1,0,0]
    WLF = [-1,0,0]
    
    if  L == "D":
        UAP = DLF	
    elif L == "U":
        UAP = ULF	
    elif L == "N":
        UAP = NLF
    elif L == "S":
        UAP = SLF
    elif L == "E":
        UAP = ELF
    elif L == "W":
        UAP = WLF
    
    if F == "D":
        FAP = DLF
    elif F == "U":
        FAP = ULF
    elif F == "N":
        FAP = NLF
    elif F == "S":
        FAP = SLF
    elif F == "E":
        FAP = ELF
    elif F == "W":
        FAP = WLF
    
    VAP = np.cross(FAP, UAP)
    DU,DV,DN = np.linalg.inv(np.column_stack((UAP, VAP, FAP))).dot(np.array(DX,DY,DZ))
    return L,F,DX,DY,DZ,DU,DV,DN

@david_r​  got it

YAHOO>>>>>>first FME Python code ...now working thank you David