PepMLM / app.py
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Update app.py
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import gradio as gr
from transformers import AutoTokenizer, AutoModelForMaskedLM
import torch
from torch.distributions.categorical import Categorical
import numpy as np
import pandas as pd
# Load the model and tokenizer
tokenizer = AutoTokenizer.from_pretrained("ChatterjeeLab/PepMLM-650M")
model = AutoModelForMaskedLM.from_pretrained("ChatterjeeLab/PepMLM-650M")
def compute_pseudo_perplexity(model, tokenizer, protein_seq, binder_seq):
sequence = protein_seq + binder_seq
tensor_input = tokenizer.encode(sequence, return_tensors='pt').to(model.device)
total_loss = 0
# Loop through each token in the binder sequence
for i in range(-len(binder_seq)-1, -1):
# Create a copy of the original tensor
masked_input = tensor_input.clone()
# Mask one token at a time
masked_input[0, i] = tokenizer.mask_token_id
# Create labels
labels = torch.full(tensor_input.shape, -100).to(model.device)
labels[0, i] = tensor_input[0, i]
# Get model prediction and loss
with torch.no_grad():
outputs = model(masked_input, labels=labels)
total_loss += outputs.loss.item()
# Calculate the average loss
avg_loss = total_loss / len(binder_seq)
# Calculate pseudo perplexity
pseudo_perplexity = np.exp(avg_loss)
return pseudo_perplexity
def generate_peptide(protein_seq, peptide_length, top_k, num_binders):
peptide_length = int(peptide_length)
top_k = int(top_k)
num_binders = int(num_binders)
binders_with_ppl = []
for _ in range(num_binders):
# Generate binder
masked_peptide = '<mask>' * peptide_length
input_sequence = protein_seq + masked_peptide
inputs = tokenizer(input_sequence, return_tensors="pt").to(model.device)
with torch.no_grad():
logits = model(**inputs).logits
mask_token_indices = (inputs["input_ids"] == tokenizer.mask_token_id).nonzero(as_tuple=True)[1]
logits_at_masks = logits[0, mask_token_indices]
# Apply top-k sampling
top_k_logits, top_k_indices = logits_at_masks.topk(top_k, dim=-1)
probabilities = torch.nn.functional.softmax(top_k_logits, dim=-1)
predicted_indices = Categorical(probabilities).sample()
predicted_token_ids = top_k_indices.gather(-1, predicted_indices.unsqueeze(-1)).squeeze(-1)
generated_binder = tokenizer.decode(predicted_token_ids, skip_special_tokens=True).replace(' ', '')
# Compute PPL for the generated binder
ppl_value = compute_pseudo_perplexity(model, tokenizer, protein_seq, generated_binder)
# Add the generated binder and its PPL to the results list
binders_with_ppl.append([generated_binder, ppl_value])
# Convert the list of lists to a pandas dataframe
df = pd.DataFrame(binders_with_ppl, columns=["Binder", "Perplexity"])
# Save the dataframe to a CSV file
output_filename = "output.csv"
df.to_csv(output_filename, index=False)
return binders_with_ppl, output_filename
# Define the Gradio interface
interface = gr.Interface(
fn=generate_peptide,
inputs=[
gr.Textbox(label="Protein Sequence", info="Enter protein sequence here", type="text"),
gr.Slider(3, 50, value=15, label="Peptide Length", step=1, info='Default value is 15'),
gr.Slider(1, 10, value=3, label="Top K Value", step=1, info='Default value is 3'),
gr.Dropdown(choices=[1, 2, 4, 8, 16, 32], label="Number of Binders", value=1)
],
outputs=[
gr.Dataframe(
headers=["Binder", "Perplexity"],
datatype=["str", "number"],
col_count=(2, "fixed")
),
gr.outputs.File(label="Download CSV")
],
title="PepMLM: Target Sequence-Conditioned Generation of Peptide Binders via Masked Language Modeling"
)
interface.launch()