Get bmu of testing data

[yanzastro]

I can use som.bmus to get the coordinates of bmus of the training data, but I want to calculate the coordinates of bmus of testing data from a pre-trained SOM. I can define something like:

def f(i, data):
    dmap = np.sum(((data[i] - som.codebook)**2)**0.5, axis=2)
    return np.asarray(np.unravel_index(np.argmin(dmap), dmap.shape, order='F'))

def get_test_bmus(som, data):    
    with Pool() as p:
        bmus = p.map(lambda i: f(i, data), np.arange(len(data)))  # use multiprocess since the testing data can be very large
    return np.asarray(bmus)

but I'm wondering if there is built-in method in a somoclu class that can do such job?

[xgdgsc]

https://github.com/peterwittek/somoclu/blob/master/src/Python/somoclu/train.py#L606 ?

[yanzastro]

thank you for your reply! I tried this and found it's pretty slow when the data vector is very large, but using multiprocessing helps.