xander.py

def make_dummy_event():
    coords=[]
    for i_eta in range(0,4):
        coords.append([])
        for i_phi in range(0,4):
            coords[i_eta].append((i_eta,i_phi,0))
    return coords

# this is the event we'd read in from a ROOT file
my_coords=make_dummy_event()
print(my_coords)

def copy_event(event):
    newevent=[]
    for i_eta in range(len(event)):
        newevent.append([])
        for i_phi in range(len(event[i_eta])):
            newevent[i_eta].append(event[i_eta][i_phi])
    return newevent

copied_event=copy_event(my_coords)
print(copied_event)

def flip_eta(event,sign):
    output=copy_event(event)
    for i_eta in range(len(event)):
        for i_phi in range(len(event[i_eta])):
            if sign<0:
                output[len(event)-i_eta-1][i_phi]=event[i_eta][i_phi]
            else:
                output[i_eta][i_phi]=event[i_eta][i_phi]
    return output

def shift_phi(event,phishift):
    output=copy_event(event)
    for i_eta in range(len(event)):
        for i_phi in range(len(event[i_eta])):
            output[i_eta][(i_phi-phishift)%len(event[i_eta])]=event[i_eta][i_phi]
    return output

flipped_event=flip_eta(my_coords,-1)
    
print("Eta flipped")
print(flipped_event)

shifted_event=shift_phi(my_coords,1)

print("Phi shifted by 1 bin")
print(shifted_event)

flipped_and_shifted_event=shift_phi(flipped_event,2)

print("Phi shifted by 1 bin")
print(flipped_and_shifted_event)