Removing duplicate triangles with numpy

remove_dup_tris.py

import numpy as np

def remove_duplicates(array_data, return_index=False, return_inverse=False):
    """Removes duplicate rows of a multi-dimensional array. Returns the
    array with the duplicates removed. If return_index is True, also
    returns the indices of array_data that result in the unique array.
    If return_inverse is True, also returns the indices of the unique
    array that can be used to reconstruct array_data."""
    unique_array_data, index_map, inverse_map = np.unique(
            array_data.view([('', array_data.dtype)] * \
                    array_data.shape[1]), return_index=True,
                    return_inverse=True)
    
    unique_array_data = unique_array_data.view(
            array_data.dtype).reshape(-1, array_data.shape[1])

    # unique returns as int64, so cast back
    index_map = np.cast['uint32'](index_map)
    inverse_map = np.cast['uint32'](inverse_map)
    
    if return_index and return_inverse:
        return unique_array_data, index_map, inverse_map
    elif return_index:
        return unique_array_data, index_map
    elif return_inverse:
         return unique_array_data, inverse_map
    
    return unique_array_data

vert_indices = np.array([[0,1,2], [2,3,4], [5,6,7], [2,3,4], [1,3,5]])
normal_indices = np.array([[9,8,7], [6,5,4], [3,2,1], [10,11,12], [13,14,15]])

print 'Original indices:'
print vert_indices
print normal_indices

unique_vert_indices, index_map = remove_duplicates(vert_indices, return_index=True)
print
print 'After removing duplicates:'
print unique_vert_indices
print normal_indices[index_map]

Thanks, also very helpful for unique'ing rows in a numpy array...