epiTOC2#

Index#

  1. Instantiate model class

  2. Define clock metadata

  3. Download clock dependencies

  4. Load features

  5. Load weights into base model

  6. Basic test

  7. Save torch model

  8. Clear directory

Let’s first import some packages:

[30]:
import os
import inspect
import shutil
import json
import torch
import pandas as pd
import pyaging as pya

Instantiate model class#

[31]:
def print_entire_class(cls):
    source = inspect.getsource(cls)
    print(source)

print_entire_class(pya.models.epiTOC2)

class epiTOC2(pyagingModel):
    def __init__(self):
        super().__init__()
        self.delta = None
        self.beta0 = None

    def preprocess(self, x):
        """
        Replace NaNs with zero; missing features should already be imputed via reference_values.
        """
        return torch.nan_to_num(x, nan=0.0)

    def forward(self, x):
        x = self.preprocess(x)

        device = x.device
        dtype = x.dtype

        delta = self.delta.to(device=device, dtype=dtype)
        beta0 = self.beta0.to(device=device, dtype=dtype)

        denom = delta * (1 - beta0)
        denom = torch.where(denom == 0, torch.ones_like(denom), denom)

        contrib = (x - beta0) / denom
        k = contrib.size(1)
        vals = 2.0 * torch.sum(contrib, dim=1) / k

        return self.postprocess(vals.unsqueeze(1))

    def postprocess(self, x):
        return x

[32]:
model = pya.models.epiTOC2()

Define clock metadata#

[33]:
model.metadata["clock_name"] = "epitoc2"
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"] = "Teschendorff, Andrew E. \"A comparison of epigenetic mitotic-like clocks for cancer risk prediction.\" Genome Medicine 12 (2020): 56."
model.metadata["doi"] = "https://doi.org/10.1186/s13073-020-00752-3"
model.metadata["notes"] = "Dynamic methylation-transmission model returning total cumulative stem-cell divisions per stem cell; an intrinsic rate additionally requires chronological age but is not this implementation's returned value."
model.metadata["research_only"] = None
model.metadata["tissue"] = ["whole blood"]  # Paper: Parameters were fitted in the Hannum whole-blood cohort.
model.metadata["predicts"] = ["mitotic age"]  # Paper: The epiTOC2 estimate is total stem-cell divisions per stem cell.
model.metadata["training_target"] = ["chronological age"]  # Paper: CpG dynamic-model parameters were fitted against age-associated methylation trajectories.
model.metadata["unit"] = ["cell divisions per stem cell"]  # Paper: The model output is total stem-cell divisions per stem cell.
model.metadata["model_type"] = "dynamic methylation transmission model"  # Paper: A dynamic model of methylation transmission with stem-cell divisions defines epiTOC2.
model.metadata["platform"] = ["Illumina 450K"]  # Paper: The Hannum training cohort was measured on the Illumina 450K array.
model.metadata["population"] = "adults"  # Paper: Model fitting used Hannum whole blood spanning ages 19 to 101.
model.metadata["journal"] = "Genome Medicine"
model.metadata["last_author"] = "Andrew E. Teschendorff"
model.metadata["n_features"] = 163
model.metadata["citations"] = 155
model.metadata["citations_date"] = "2026-07-05"

Download clock dependencies#

Download coefficient file#

[34]:
coeff_url = "https://raw.githubusercontent.com/bio-learn/biolearn/master/biolearn/data/EpiTOC2.csv"
os.system(f"curl -L {coeff_url} -o EpiTOC2.csv")

[34]:
0

Load features#

From Excel file#

[35]:
df = pd.read_csv('EpiTOC2.csv', index_col=0)
df['feature'] = df.index.astype(str)
model.features = df['feature'].tolist()

Load weights into base model#

[36]:
#### From CSV file

[37]:
model.delta = torch.tensor(df['delta'].values, dtype=torch.float32).unsqueeze(0)
model.beta0 = torch.tensor(df['beta0'].values, dtype=torch.float32).unsqueeze(0)
model.base_model = None

[38]:
#### Linear model

Not used; computation happens in the model forward#

[39]:
model.reference_values = [-1]*len(model.features)

model.reference_values = [0.0] * len(model.features)

[40]:
model.preprocess_name = "mean"
model.preprocess_dependencies = None
[41]:
model.preprocess_name = "nan_to_zero"
model.preprocess_dependencies = None

model.postprocess_name = None model.postprocess_dependencies = None

[42]:
pya.utils.print_model_details(model)

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

training: True
metadata: {'approved_by_author': '⌛',
 'citation': 'Teschendorff, Andrew E. "A comparison of epigenetic mitotic-like '
             'clocks for cancer risk prediction." Genome Medicine 12.1 (2020): '
             '56.',
 'clock_name': 'epitoc2',
 'data_type': 'methylation',
 'doi': 'https://doi.org/10.1186/s13073-020-00752-3',
 'notes': 'Stem cell division rate estimate using EpiTOC2.',
 'research_only': None,
 'species': 'Homo sapiens',
 'version': None,
 'year': 2020}
reference_values: [-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1]... [Total elements: 163]
preprocess_name: 'nan_to_zero'
preprocess_dependencies: None
postprocess_name: None
postprocess_dependencies: None
features: ['cg00043095', 'cg00347369', 'cg00397986', 'cg00466268', 'cg00884606', 'cg00916884', 'cg01435574', 'cg01537995', 'cg01587896', 'cg01699217', 'cg01783070', 'cg01830294', 'cg02150988', 'cg02186542', 'cg02266732', 'cg02631468', 'cg02726121', 'cg02796545', 'cg02964724', 'cg03045635', 'cg03111498', 'cg03140968', 'cg03181582', 'cg03430846', 'cg03450948', 'cg03603951', 'cg03874199', 'cg04188273', 'cg04408488', 'cg04431946']... [Total elements: 163]
base_model_features: None
base_model: None
delta: [4.999999873689376e-05, 4.999999873689376e-05, 4.999999873689376e-05, 9.999999747378752e-05, 9.999999747378752e-05, 4.999999873689376e-05, 4.999999873689376e-05, 4.999999873689376e-05, 9.999999747378752e-05, 4.999999873689376e-05, 4.999999873689376e-05, 0.0002500000118743628, 9.999999747378752e-05, 4.999999873689376e-05, 4.999999873689376e-05, 4.999999873689376e-05, 4.999999873689376e-05, 9.999999747378752e-05, 4.999999873689376e-05, 0.0002500000118743628, 9.999999747378752e-05, 4.999999873689376e-05, 4.999999873689376e-05, 4.999999873689376e-05, 9.999999747378752e-05, 4.999999873689376e-05, 4.999999873689376e-05, 9.999999747378752e-06, 4.999999873689376e-05, 4.999999873689376e-05]... [Tensor of shape torch.Size([1, 163])]
beta0: [0.019999999552965164, 0.05000000074505806, 0.05000000074505806, 0.05000000074505806, 0.009999999776482582, 0.05000000074505806, 0.05000000074505806, 0.05000000074505806, 0.029999999329447746, 0.05000000074505806, 0.03999999910593033, 0.0, 0.029999999329447746, 0.05000000074505806, 0.019999999552965164, 0.05000000074505806, 0.029999999329447746, 0.019999999552965164, 0.05000000074505806, 0.029999999329447746, 0.029999999329447746, 0.03999999910593033, 0.05000000074505806, 0.05000000074505806, 0.029999999329447746, 0.009999999776482582, 0.029999999329447746, 0.019999999552965164, 0.019999999552965164, 0.03999999910593033]... [Tensor of shape torch.Size([1, 163])]

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


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


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

Basic test#

[43]:
torch.manual_seed(42)
input = torch.randn(10, len(model.features), dtype=float)
model.eval()
model.to(float)
pred = model(input)
pred

[43]:
tensor([[ 1562.6673],
        [-3824.6137],
        [  645.1144],
        [-1810.9748],
        [ -142.2699],
        [ 1630.9714],
        [ 9229.4758],
        [ 4666.7934],
        [ 5489.9210],
        [ 1256.8648]], dtype=torch.float64)

Save torch model#

[44]:
torch.save(model, f"../weights/{model.metadata['clock_name']}.pt")

Clear directory#

[45]:
# 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 file: EpiTOC2.csv