PedBE#

Index#

  1. Instantiate model class

  2. Define clock metadata

  3. Download clock dependencies

  4. Load features

  5. Load weights into base model

  6. Load reference values

  7. Load preprocess and postprocess objects

  8. Check all clock parameters

  9. Basic test

  10. Save torch model

  11. Clear directory

Let’s first import some packages:

[1]:
import os
import inspect
import shutil
import json
import torch
import pandas as pd
import pyaging as pya

Instantiate model class#

[2]:
def print_entire_class(cls):
    source = inspect.getsource(cls)
    print(source)

print_entire_class(pya.models.PedBE)
class PedBE(pyagingModel):
    def __init__(self):
        super().__init__()

    def preprocess(self, x):
        return x

    def postprocess(self, x):
        """
        Applies an anti-logarithmic linear transformation to a PyTorch tensor.
        """
        adult_age = 20

        # Create a mask for negative and non-negative values
        mask_negative = x < 0
        mask_non_negative = ~mask_negative

        # Initialize the result tensor
        age_tensor = torch.empty_like(x)

        # Exponential transformation for negative values
        age_tensor[mask_negative] = (1 + adult_age) * torch.exp(x[mask_negative]) - 1

        # Linear transformation for non-negative values
        age_tensor[mask_non_negative] = (1 + adult_age) * x[
            mask_non_negative
        ] + adult_age

        return age_tensor

[3]:
model = pya.models.PedBE()

Define clock metadata#

[4]:
model.metadata["clock_name"] = "pedbe"
model.metadata["data_type"] = "DNA methylation"  # Paper: The study constructs clocks from DNA methylation measurements.
model.metadata["species"] = "Homo sapiens"  # Paper: The analyzed samples and clock are human.
model.metadata["year"] = 2020
model.metadata["approved_by_author"] = "⌛"
model.metadata["citation"] = "McEwen, Lisa M., et al. \"The PedBE clock accurately estimates DNA methylation age in pediatric buccal cells.\" Proceedings of the National Academy of Sciences 117 (2020): 23329–23335."
model.metadata["doi"] = "https://doi.org/10.1073/pnas.1820843116"
model.metadata["notes"] = "Pediatric chronological-age estimator developed specifically for noninvasive buccal epithelial-cell samples."
model.metadata["research_only"] = None
model.metadata["tissue"] = ["buccal epithelium"]  # Paper: The model was developed and tested in buccal epithelial cells.
model.metadata["predicts"] = ["chronological age"]  # Paper: PedBE estimates DNA methylation age in children.
model.metadata["training_target"] = ["chronological age"]  # Paper: Elastic-net regression selected CpGs predictive of participant age.
model.metadata["unit"] = ["years"]  # Paper: Age prediction errors and estimates are reported in years.
model.metadata["model_type"] = "elastic net regression"  # Paper: The clock was developed using elastic-net penalized regression.
model.metadata["platform"] = ["Illumina 450K", "Illumina EPIC"]  # Paper: The pooled pediatric buccal cohorts included 450K and EPIC methylation profiles.
model.metadata["population"] = "children and adolescents"  # Paper: The study included 1,721 healthy individuals aged 0 to 20 years.
model.metadata["journal"] = "Proceedings of the National Academy of Sciences of the United States of America"
model.metadata["last_author"] = "Michael S. Kobor"
model.metadata["n_features"] = 94
model.metadata["citations"] = 292
model.metadata["citations_date"] = "2026-07-05"

Download clock dependencies#

Download GitHub repository#

[5]:
github_url = "https://github.com/kobor-lab/Public-Scripts"
github_folder_name = github_url.split('/')[-1].split('.')[0]
os.system(f"git clone {github_url}")
[5]:
0

Load features#

From CSV file#

[6]:
df = pd.read_csv('Public-Scripts/datcoefInteresting94.csv')
df['feature'] = df['ID']
df['coefficient'] = df['Coef']

model.features = df['feature'][1:].tolist()

Load weights into base model#

[7]:
weights = torch.tensor(df['coefficient'][1:].tolist()).unsqueeze(0)
intercept = torch.tensor([df['coefficient'][0]])

Linear model#

[8]:
base_model = pya.models.LinearModel(input_dim=len(model.features))

base_model.linear.weight.data = weights.float()
base_model.linear.bias.data = intercept.float()

model.base_model = base_model

Load reference values#

[9]:
model.reference_values = None

Load preprocess and postprocess objects#

[10]:
model.preprocess_name = None
model.preprocess_dependencies = None
[11]:
model.postprocess_name = 'anti_log_linear'
model.postprocess_dependencies = None

Check all clock parameters#

[12]:
pya.utils.print_model_details(model)

%==================================== Model Details ====================================%
Model Attributes:

training: True
metadata: {'approved_by_author': '⌛',
 'citation': 'McEwen, Lisa M., et al. "The PedBE clock accurately estimates '
             'DNA methylation age in pediatric buccal cells." Proceedings of '
             'the National Academy of Sciences 117.38 (2020): 23329-23335.',
 'clock_name': 'pedbe',
 'data_type': 'methylation',
 'doi': 'https://doi.org/10.1073/pnas.1820843116',
 'notes': None,
 'research_only': None,
 'species': 'Homo sapiens',
 'version': None,
 'year': 2019}
reference_values: None
preprocess_name: None
preprocess_dependencies: None
postprocess_name: 'anti_log_linear'
postprocess_dependencies: None
features: ['cg00059225', 'cg00085493', 'cg00095976', 'cg00609333', 'cg01287592', 'cg01704999', 'cg02209075', 'cg02310103', 'cg02426178', 'cg02821342', 'cg02980055', 'cg03020208', 'cg03466124', 'cg03473016', 'cg03493146', 'cg03555227', 'cg04221461', 'cg04452203', 'cg04937184', 'cg04948475', 'cg05024939', 'cg05271255', 'cg05923197', 'cg05928290', 'cg06048436', 'cg06144905', 'cg06198384', 'cg06416491', 'cg06430061', 'cg06455149']... [Total elements: 94]
base_model_features: None

%==================================== Model Details ====================================%
Model Structure:

base_model: LinearModel(
  (linear): Linear(in_features=94, out_features=1, bias=True)
)

%==================================== Model Details ====================================%
Model Parameters and Weights:

base_model.linear.weight: [0.021960020065307617, -0.10039610415697098, 0.007872418500483036, 0.022823642939329147, -0.055414702743291855, -0.09757450968027115, 0.13820089399814606, -0.08401073515415192, -0.3583613932132721, -0.13026674091815948, -0.1387656182050705, 0.21038542687892914, -0.022311074659228325, 0.00015541094762738794, -0.1624089926481247, 0.6385841369628906, 0.03457474708557129, -0.026989279314875603, -0.05423707515001297, -0.0008215174311771989, 0.14885476231575012, -0.1249200701713562, 0.039291542023420334, 0.15890249609947205, -0.1548999398946762, 0.31524088978767395, 0.003525394480675459, -0.19241906702518463, -0.017204945906996727, 0.08637607842683792]... [Tensor of shape torch.Size([1, 94])]
base_model.linear.bias: tensor([-2.0973])

%==================================== Model Details ====================================%

Basic test#

[13]:
torch.manual_seed(42)
input = torch.randn(10, len(model.features), dtype=float)
model.eval()
model.to(float)
pred = model(input)
pred
[13]:
tensor([[-0.8260],
        [-0.4025],
        [ 2.6240],
        [-0.3707],
        [-0.8111],
        [-0.4591],
        [16.2847],
        [ 8.2621],
        [ 2.4227],
        [ 4.0783]], dtype=torch.float64, grad_fn=<IndexPutBackward0>)

Save torch model#

[14]:
torch.save(model, f"../weights/{model.metadata['clock_name']}.pt")

Clear directory#

[15]:
# Function to remove a folder and all its contents
def remove_folder(path):
    try:
        shutil.rmtree(path)
        print(f"Deleted folder: {path}")
    except Exception as e:
        print(f"Error deleting folder {path}: {e}")

# Get a list of all files and folders in the current directory
all_items = os.listdir('.')

# Loop through the items
for item in all_items:
    # Check if it's a file and does not end with .ipynb
    if os.path.isfile(item) and not item.endswith('.ipynb'):
        os.remove(item)
        print(f"Deleted file: {item}")
    # Check if it's a folder
    elif os.path.isdir(item):
        remove_folder(item)
Deleted folder: Public-Scripts