Safetensors
File size: 7,551 Bytes
aa45001
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
from .paths import ROOT, BACKBONE, PREDICTOR, DIFFUSION, TRAIN, configure
configure()
import argparse
import numpy as np
import torch
from absl import flags
from transformers import AutoTokenizer, EsmModel
from datasets import load_from_disk
from .continuous import GaussianDiffusionSampler, DiffusionProteinModel
from .discrete import MultinomialDiffusion
from .unet import tabularUnet
from .predictor import MultitaskProteinModel
FLAGS = flags.FLAGS
METAL_LABELS = ['Ag','Cd','Co','Cu','Fe','Hg','Mn','Mo','Ni','Pb','Pt','V','W','Zn','NA']
TOKEN_DROPOUT_SCALE = 0.88
CODI_CKPT, PRED_CKPT, TRAIN_DS, ESM_NAME = map(str, (DIFFUSION,PREDICTOR,TRAIN,BACKBONE))

def build_hparams():
    ns = argparse.Namespace()
    ns.date = 'test'
    ns.attempts = '1'
    ns.output_model_path = str(ROOT/'runs')
    ns.num_workers = 8
    ns.num_linear_layers = 3
    ns.batch_size = 5
    ns.devices = 1
    ns.special_prefix = None
    ns.focal_gamma = 1
    ns.lr = 1e-3
    ns.eps = 0.4
    ns.n_splits = 2
    ns.epochs = 100
    ns.save_top_k = 3
    return ns


def define_flags():
    if not FLAGS.is_parsed():
        FLAGS([""])
    d = {
        'encoder_dim_con': ('string', "64,128,256"), 'encoder_dim_dis': ('string', "64,128,256"),
        'nf_con': ('int', 16), 'nf_dis': ('int', 64),
        'input_size': ('int', None), 'cond_size': ('int', None), 'output_size': ('int', None),
        'activation': ('string', 'relu'), 'nf': ('int', None),
        'hidden_size': ('int', 768), 'num_layers': ('int', 12), 'num_heads': ('int', 12),
        'intermediate_size': ('int', 4 * 768), 'max_seq_length': ('int', 1280),
        'T': ('int', 50), 'beta_1': ('float', 0.00001), 'beta_T': ('float', 0.02),
    }
    for name, (kind, default) in d.items():
        if not hasattr(FLAGS, name):
            {'string': flags.DEFINE_string, 'int': flags.DEFINE_integer,
             'float': flags.DEFINE_float}[kind](name, default, help=name)
    if not hasattr(FLAGS, 'encoder_dim'):
        flags.DEFINE_multi_integer('encoder_dim', None, help='encoder_dim')
    if not hasattr(FLAGS, 'mean_type'):
        flags.DEFINE_enum('mean_type', 'epsilon', ['xprev', 'xstart', 'epsilon'], help='mean type')
    if not hasattr(FLAGS, 'var_type'):
        flags.DEFINE_enum('var_type', 'fixedsmall', ['fixedlarge', 'fixedsmall'], help='var type')


def load_diffusion_models(checkpoint_path, base_model, device):
    ckpt = torch.load(checkpoint_path, map_location=device)

    model_con_state = ckpt['model_con']
    base_keys = [k for k in model_con_state if 'base_model' in k]
    if base_keys:
        base_state = {k.replace('base_model.', ''): model_con_state[k] for k in base_keys}
        base_model.load_state_dict(base_state, strict=False)
        print("Loaded base model weights from CoDi checkpoint")

    def strip(sd):
        return {k.replace('module.', ''): v for k, v in sd.items()}
    if 'module.' in next(iter(ckpt['model_con'])):
        ckpt['model_con'] = strip(ckpt['model_con'])
    if 'module.' in next(iter(ckpt['model_dis'])):
        ckpt['model_dis'] = strip(ckpt['model_dis'])

    FLAGS.input_size, FLAGS.cond_size, FLAGS.output_size = 1280, 15, 1280
    FLAGS.encoder_dim = [int(x) for x in FLAGS.encoder_dim_con.split(',')]
    FLAGS.nf = FLAGS.nf_con
    FLAGS.hidden_size, FLAGS.num_layers, FLAGS.num_heads = 768, 12, 12
    FLAGS.intermediate_size, FLAGS.max_seq_length = 4 * 768, 1280

    model_con = DiffusionProteinModel(base_model, FLAGS).to(device)
    filtered = {}
    for k, v in ckpt['model_con'].items():
        if not k.startswith('base_model.'):
            filtered[k] = v
        else:
            bk = k.replace('base_model.', '')
            if bk in base_model.state_dict() and v.shape == base_model.state_dict()[bk].shape:
                filtered[k] = v
    model_con.load_state_dict(filtered, strict=False)

    FLAGS.input_size, FLAGS.cond_size, FLAGS.output_size = 15, 1280, 15
    FLAGS.encoder_dim = [int(x) for x in FLAGS.encoder_dim_dis.split(',')]
    FLAGS.nf = FLAGS.nf_dis
    model_dis = tabularUnet(FLAGS).to(device)
    model_dis.load_state_dict(ckpt['model_dis'])

    trainer_dis = MultinomialDiffusion(
        num_classes=np.array([15]), shape=torch.Size([10, 15]), denoise_fn=model_dis,
        FLAGS=FLAGS, timesteps=FLAGS.T, loss_type='vb_stochastic').to(device)
    net_sampler = GaussianDiffusionSampler(
        model_con, FLAGS.beta_1, FLAGS.beta_T, FLAGS.T,
        mean_type=FLAGS.mean_type, var_type=FLAGS.var_type).to(device)
    return model_con, model_dis, trainer_dis, net_sampler


class Sampler:
    def __init__(self, cfg, device='cuda:0'):
        self.cfg = cfg
        self.device = torch.device(device)
        define_flags()

        self.tokenizer = AutoTokenizer.from_pretrained(ESM_NAME)
        self.cys_id = self.tokenizer.convert_tokens_to_ids('C')
        self.cls_id = self.tokenizer.cls_token_id
        self.eos_id = self.tokenizer.eos_token_id

        ds = load_from_disk(TRAIN_DS)
        labels = np.stack([l for b in ds['anchor_labels'] for l in b])
        cw = 1.0 / (labels.sum(axis=0) + 1e-6)
        cw = torch.tensor(cw / cw.sum() * labels.shape[1], dtype=torch.float32).to(self.device)

        hp = build_hparams()
        esm = EsmModel.from_pretrained(ESM_NAME).cpu()
        base_model = MultitaskProteinModel.load_from_checkpoint(
            PRED_CKPT, hparams=hp, esm_model=esm, num_layers_to_finetune=2,
            input_dim=1280, output_dim=15, class_weights=cw).cpu()

        esm2 = EsmModel.from_pretrained(ESM_NAME).cpu()
        self.predictor = MultitaskProteinModel.load_from_checkpoint(
            PRED_CKPT, hparams=hp, esm_model=esm2, num_layers_to_finetune=2,
            input_dim=1280, output_dim=15, class_weights=cw).to(self.device).eval()

        self.model_con, self.model_dis, self.trainer_dis, self.net_sampler = \
            load_diffusion_models(CODI_CKPT, base_model, self.device)
        self.model_con.eval()
        self.model_dis.eval()

        # Gradients are needed only with respect to the latent.
        for m in (self.predictor, self.model_con, self.model_dis):
            for p in m.parameters():
                p.requires_grad_(False)

        self.W = self.predictor.esm_model.embeddings.word_embeddings.weight
        self.threshold = self.predictor.classification_thresholds[cfg.target_idx].item()

        self.vocab_mask = torch.full((33,), float('-inf'), device=self.device)
        self.vocab_mask[4:24] = 0.0
        self.aa_bias = torch.zeros(33, device=self.device)
        self.aa_bias[self.cys_id] = cfg.cys_logit_bias

        self.others = [i for i in range(15) if i != cfg.target_idx]
        print(f"target={METAL_LABELS[cfg.target_idx]} idx={cfg.target_idx} "
              f"threshold={self.threshold:.4f} cys_token={self.cys_id}")

    @torch.no_grad()
    def hard_decode(self, x, attn_len):
        logits = self.model_con.decode_embeddings(x[:, :attn_len])
        biased = logits + self.vocab_mask[None, None, :] + self.aa_bias[None, None, :]
        toks = torch.argmax(biased, dim=-1)
        return [self.tokenizer.decode(t, skip_special_tokens=True).replace(' ', '')
                for t in toks]

    @torch.no_grad()
    def score(self, seqs):
        enc = self.tokenizer(seqs, return_tensors='pt', padding=True)
        enc = {k: v.to(self.device) for k, v in enc.items()}
        probs, fires, _ = self.predictor.predict(input_ids=enc['input_ids'],
                                                 attention_masks=enc['attention_mask'])
        return probs, fires