Replace objetive function in Word2Vec Gensim

I'm doing my final degree project. I need to create an extended version of the word2vec algorithm, changing the default objective function of the original paper. This has already been done (check this paper). In that paper, they only say the new objective function, but they do not say how they have run the model.

Now, I need to extend that model too, with another function, but I'm not sure if I have to implement word2vec myself with the new function, or there is a way to replace it in the Gensim word2vec implementation.

I have checked the Word2Vec Gensim documentation but I have not seen any parameter to do this. Do you have any idea how to do it? It is even possible?

I was unsure if this StackExchange site was the correct one, maybe https://ai.stackexchange.com/ is more appropriate.

Solution

There's no official support in Gensim for simply dropping in your own objective function.

However, the full source code is available – https://github.com/RaRe-Technologies/gensim – so by editing it, or using it as a model for your own implementation, you could theoretically do anything.

Beware, though:

the code has gone through a lot of optimization & customization for new options that may not be relevant to your needs, so may not be the most clean & simple starting point
for performance, the core routines are written in Cython – see the .pyx files – which can be especially hard to debug, and rely on library bulk array functions that may obscure how to implement your alternate function instead