gd_mf_weights.cc has bug in writing out features for the right namespace

[szipkin]

Bug:

vowpal_wabbit/library/gd_mf_weights.cc

Line 94 in 45a8a7f

// write out features for right namespace

The current code for the right namespace is incorrectly pointing to the left.indices, not right. As a result, it generates wrong output for the right namespace.

// write out features for left namespace
features& left = ec->feature_space[left_ns];
for (size_t i = 0; i < left.size(); ++i)
{ left_linear << left.space_names[i].get()->second << '\t' << weights[left.indicies[i]];

  left_quadratic << left.space_names[i].get()->second;
  for (size_t k = 1; k <= rank; k++)
    left_quadratic << '\t' << weights[(left.indicies[i] + k)];
}
left_linear << endl;
left_quadratic << endl;

// write out features for right namespace
features& right = ec->feature_space[right_ns];
for (size_t i = 0; i < right.size(); ++i)
{ right_linear << right.space_names[i].get()->second << '\t' << weights[left.indicies[i]];

  right_quadratic << right.space_names[i].get()->second;
  for (size_t k = 1; k <= rank; k++)
    right_quadratic << '\t' << weights[(left.indicies[i] + k + rank)];
}
right_linear << endl;
right_quadratic << endl;

[ataymano]

Yes, that seems correct. Do you want to send pull request?

[szipkin]

It's my first time creating a pull request. Let me know if I didn't do it correctly. Thanks.

[ataymano]

Thanks for creating pull request. It looks good.
But I have added one comment there - sorry, haven't noticed one mistake in initial proposal.

[jackgerrits]

Looks like #1874 has resolved this. Please reopen if there is still an issue.