Samplers: Part 2

This commit is contained in:
somebody
2023-02-26 17:22:54 -06:00
parent f882979c88
commit af73527be0
3 changed files with 385 additions and 418 deletions

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@@ -349,57 +349,6 @@ def kobold_sample_dynamic(key, logits, rpargs, sampler_order: Optional[np.ndarra
# probability distribution)
return jax.random.categorical(key, logits, -1).astype(np.uint32)
def apply_repetition_penalty_static(logits, tokens, repetition_penalty, generated_index, gen_length, rpslope, rprange):
'''
This gets called by generate_loop_fn to apply repetition penalty
to the 1D array logits using the provided 1D array of tokens to penalize
'''
rpslope = jnp.int32(rpslope)
rprange = jnp.int32(rprange)
clipped_rprange = jax.lax.cond(rprange > 0, lambda x: x, lambda x: tokens.shape[-1], rprange)
penalty_arange = jnp.roll(jnp.arange(tokens.shape[-1]) + (clipped_rprange - tokens.shape[-1]), generated_index, axis=-1)
# Make a new array with the same length as the tokens array but with
# each element replaced by the value at the corresponding index in the
# logits array; e.g.
# if logits is [77, 5, 3, 98] and tokens is [0, 1, 2, 3, 2, 3, 1],
# then penalty_logits will be [77, 5, 3, 98, 3, 98, 5]
penalty_logits = jnp.take(logits, tokens)
# Repetition penalty slope
def apply_slope(carry):
repetition_penalty, rprange = carry
_penalty = (penalty_arange/(rprange - 1)) * 2 - 1
_penalty = (rpslope * _penalty) / (1 + jnp.abs(_penalty) * (rpslope - 1))
_penalty = 1 + ((_penalty + 1) / 2) * (repetition_penalty - 1)
return _penalty
repetition_penalty = jax.lax.cond(
(rpslope != 0.0) & (rprange > 0), # Not a typo; do not use `and` here, it makes JAX crash
apply_slope,
lambda carry: jnp.full(tokens.shape, carry[0]),
(repetition_penalty, rprange),
)
# Divide positive values by repetition_penalty and multiply negative
# values by repetition_penalty (the academic publication that described
# this technique actually just only divided, but that would cause tokens
# with negative logits to become more likely, which is obviously wrong)
if koboldai_vars.use_alt_rep_pen:
penalty_logits = jnp.where(
penalty_arange >= 0,
penalty_logits - jnp.log(repetition_penalty),
penalty_logits,
)
else:
penalty_logits = jnp.where(
penalty_arange >= 0,
jnp.where(
penalty_logits > 0,
penalty_logits/repetition_penalty,
penalty_logits*repetition_penalty,
),
penalty_logits,
)
# Finally, put those penalized logit values back into their original
# positions in the logits array
return logits.at[tokens].set(penalty_logits)
def kobold_sample_static(key, logits, rpargs, sampler_order: Optional[np.ndarray] = None, top_p=0.9, temp=0.5, top_k=0, tfs=1.0, typical=1.0, top_a=0.0):
'''