tools-only ML Model Builder
Business Case
Problem Statement
Construction prediction challenges:
- Complex relationships between variables
- Limited historical data utilization
- Need for multiple prediction targets
- Model validation and deployment
Solution
Comprehensive ML model building framework for construction predictions with data preprocessing, model training, evaluation, and export capabilities.
Technical Implementation
import pandas as pd
import numpy as np
from typing import Dict, Any, List, Optional, Tuple, Callable
from dataclasses import dataclass, field
from datetime import datetime
from enum import Enum
import json
import math
class PredictionTarget(Enum):
COST = "cost"
DURATION = "duration"
RISK_SCORE = "risk_score"
PRODUCTIVITY = "productivity"
QUALITY = "quality"
class AlgorithmType(Enum):
LINEAR_REGRESSION = "linear_regression"
RIDGE_REGRESSION = "ridge_regression"
KNN = "knn"
DECISION_TREE = "decision_tree"
ENSEMBLE = "ensemble"
class FeatureType(Enum):
NUMERIC = "numeric"
CATEGORICAL = "categorical"
BOOLEAN = "boolean"
DATE = "date"
@dataclass
class Feature:
name: str
feature_type: FeatureType
importance: float = 0.0
categories: List[str] = field(default_factory=list)
@dataclass
class ModelMetrics:
mae: float
mape: float
rmse: float
r_squared: float
samples: int
@dataclass
class TrainedModel:
model_id: str
target: PredictionTarget
algorithm: AlgorithmType
features: List[Feature]
metrics: ModelMetrics
coefficients: Dict[str, float]
intercept: float
trained_at: datetime
training_samples: int
class MLModelBuilder:
"""Build and train ML models for construction predictions."""
def __init__(self, project_name: str = "Construction ML"):
self.project_name = project_name
self.models: Dict[str, TrainedModel] = {}
self.feature_stats: Dict[str, Dict[str, float]] = {}
self.categorical_encodings: Dict[str, Dict[str, int]] = {}
def prepare_data(self, df: pd.DataFrame,
target_column: str,
feature_columns: List[str],
test_size: float = 0.2) -> Tuple[np.ndarray, np.ndarray,
np.ndarray, np.ndarray]:
"""Prepare and split data for training."""
# Handle missing values
df = df.dropna(subset=[target_column] + feature_columns)
# Encode categorical features
X_processed = []
for col in feature_columns:
if df[col].dtype == 'object':
# Categorical encoding
if col not in self.categorical_encodings:
unique_vals = df[col].unique()
self.categorical_encodings[col] = {v: i for i, v in enumerate(unique_vals)}
encoded = df[col].map(self.categorical_encodings[col]).fillna(0)
X_processed.append(encoded.values)
else:
# Numeric - normalize
values = df[col].values
if col not in self.feature_stats:
self.feature_stats[col] = {
'mean': np.mean(values),
'std': np.std(values) or 1
}
normalized = (values - self.feature_stats[col]['mean']) / self.feature_stats[col]['std']
X_processed.append(normalized)
X = np.column_stack(X_processed)
y = df[target_column].values
# Train-test split
n = len(df)
indices = np.random.permutation(n)
test_n = int(n * test_size)
test_indices = indices[:test_n]
train_indices = indices[test_n:]
X_train = X[train_indices]
X_test = X[test_indices]
y_train = y[train_indices]
y_test = y[test_indices]
return X_train, X_test, y_train, y_test
def train_linear_regression(self, X: np.ndarray, y: np.ndarray,
regularization: float = 0.0) -> Tuple[np.ndarray, float]:
"""Train linear regression model."""
# Add intercept
X_with_intercept = np.column_stack([np.ones(len(X)), X])
if regularization > 0:
# Ridge regression
n_features = X_with_intercept.shape[1]
reg_matrix = regularization * np.eye(n_features)
reg_matrix[0, 0] = 0 # Don't regularize intercept
XtX = X_with_intercept.T @ X_with_intercept + reg_matrix
else:
XtX = X_with_intercept.T @ X_with_intercept
try:
XtX_inv = np.linalg.inv(XtX)
beta = XtX_inv @ X_with_intercept.T @ y
except np.linalg.LinAlgError:
# Use pseudoinverse if singular
beta = np.linalg.pinv(X_with_intercept) @ y
return beta[1:], beta[0]
def train_knn_model(self, X_train: np.ndarray, y_train: np.ndarray,
k: int = 5) -> Callable:
"""Create k-NN prediction function."""
def predict(X_new: np.ndarray) -> np.ndarray:
predictions = []
for x in X_new:
distances = np.sqrt(np.sum((X_train - x) ** 2, axis=1))
nearest_indices = np.argsort(distances)[:k]
nearest_values = y_train[nearest_indices]
predictions.append(np.mean(nearest_values))
return np.array(predictions)
return predict
def calculate_metrics(self, y_true: np.ndarray,
y_pred: np.ndarray) -> ModelMetrics:
"""Calculate model performance metrics."""
residuals = y_true - y_pred
mae = np.mean(np.abs(residuals))
mape = np.mean(np.abs(residuals / (y_true + 1e-10))) * 100
rmse = math.sqrt(np.mean(residuals ** 2))
# R-squared
ss_res = np.sum(residuals ** 2)
ss_tot = np.sum((y_true - np.mean(y_true)) ** 2)
r_squared = 1 - (ss_res / (ss_tot + 1e-10))
return ModelMetrics(
mae=round(mae, 2),
mape=round(mape, 2),
rmse=round(rmse, 2),
r_squared=round(r_squared, 4),
samples=len(y_true)
)
def build_model(self, df: pd.DataFrame,
target_column: str,
feature_columns: List[str],
target_type: PredictionTarget,
algorithm: AlgorithmType = AlgorithmType.LINEAR_REGRESSION,
model_id: str = None,
**kwargs) -> TrainedModel:
"""Build and train a prediction model."""
model_id = model_id or f"{target_type.value}_{datetime.now().strftime('%Y%m%d_%H%M%S')}"
# Prepare data
X_train, X_test, y_train, y_test = self.prepare_data(
df, target_column, feature_columns,
test_size=kwargs.get('test_size', 0.2)
)
# Train model based on algorithm
if algorithm == AlgorithmType.LINEAR_REGRESSION:
coefficients, intercept = self.train_linear_regression(X_train, y_train)
y_pred = X_test @ coefficients + intercept
elif algorithm == AlgorithmType.RIDGE_REGRESSION:
coefficients, intercept = self.train_linear_regression(
X_train, y_train,
regularization=kwargs.get('alpha', 1.0)
)
y_pred = X_test @ coefficients + intercept
elif algorithm == AlgorithmType.KNN:
predict_fn = self.train_knn_model(
X_train, y_train,
k=kwargs.get('k', 5)
)
y_pred = predict_fn(X_test)
coefficients = np.zeros(len(feature_columns))
intercept = np.mean(y_train)
else:
# Default to linear
coefficients, intercept = self.train_linear_regression(X_train, y_train)
y_pred = X_test @ coefficients + intercept
# Calculate metrics
metrics = self.calculate_metrics(y_test, y_pred)
# Calculate feature importance (based on coefficient magnitude)
coef_abs = np.abs(coefficients)
importance_sum = np.sum(coef_abs) or 1
importances = coef_abs / importance_sum
features = [
Feature(
name=col,
feature_type=FeatureType.CATEGORICAL if col in self.categorical_encodings else FeatureType.NUMERIC,
importance=round(float(importances[i]), 4),
categories=list(self.categorical_encodings.get(col, {}).keys())
)
for i, col in enumerate(feature_columns)
]
# Create model object
model = TrainedModel(
model_id=model_id,
target=target_type,
algorithm=algorithm,
features=features,
metrics=metrics,
coefficients={col: float(coefficients[i]) for i, col in enumerate(feature_columns)},
intercept=float(intercept),
trained_at=datetime.now(),
training_samples=len(X_train)
)
self.models[model_id] = model
return model
def predict(self, model_id: str, features: Dict[str, Any]) -> Dict[str, Any]:
"""Make prediction using trained model."""
if model_id not in self.models:
return {'error': 'Model not found'}
model = self.models[model_id]
# Process features
feature_values = []
for feat in model.features:
value = features.get(feat.name)
if feat.feature_type == FeatureType.CATEGORICAL:
encoded = self.categorical_encodings.get(feat.name, {}).get(value, 0)
feature_values.append(encoded)
else:
# Normalize
stats = self.feature_stats.get(feat.name, {'mean': 0, 'std': 1})
normalized = (value - stats['mean']) / stats['std']
feature_values.append(normalized)
# Calculate prediction
feature_array = np.array(feature_values)
coef_array = np.array([model.coefficients[f.name] for f in model.features])
prediction = float(np.dot(feature_array, coef_array) + model.intercept)
return {
'model_id': model_id,
'prediction': round(prediction, 2),
'model_metrics': {
'mae': model.metrics.mae,
'r_squared': model.metrics.r_squared
},
'feature_contributions': {
f.name: round(feature_values[i] * model.coefficients[f.name], 2)
for i, f in enumerate(model.features)
}
}
def compare_models(self, model_ids: List[str] = None) -> pd.DataFrame:
"""Compare multiple models."""
models = [self.models[m] for m in (model_ids or self.models.keys())]
data = [{
'Model ID': m.model_id,
'Target': m.target.value,
'Algorithm': m.algorithm.value,
'MAE': m.metrics.mae,
'MAPE %': m.metrics.mape,
'RMSE': m.metrics.rmse,
'R²': m.metrics.r_squared,
'Training Samples': m.training_samples,
'Features': len(m.features)
} for m in models]
return pd.DataFrame(data)
def get_feature_importance(self, model_id: str) -> pd.DataFrame:
"""Get feature importance for a model."""
if model_id not in self.models:
return pd.DataFrame()
model = self.models[model_id]
data = [{
'Feature': f.name,
'Importance': f.importance,
'Coefficient': model.coefficients.get(f.name, 0),
'Type': f.feature_type.value
} for f in sorted(model.features, key=lambda x: x.importance, reverse=True)]
return pd.DataFrame(data)
def export_model(self, model_id: str, output_path: str) -> str:
"""Export model to JSON."""
if model_id not in self.models:
return ""
model = self.models[model_id]
export_data = {
'model_id': model.model_id,
'target': model.target.value,
'algorithm': model.algorithm.value,
'trained_at': model.trained_at.isoformat(),
'training_samples': model.training_samples,
'metrics': {
'mae': model.metrics.mae,
'mape': model.metrics.mape,
'rmse': model.metrics.rmse,
'r_squared': model.metrics.r_squared
},
'coefficients': model.coefficients,
'intercept': model.intercept,
'features': [
{
'name': f.name,
'type': f.feature_type.value,
'importance': f.importance
}
for f in model.features
],
'preprocessing': {
'feature_stats': self.feature_stats,
'categorical_encodings': self.categorical_encodings
}
}
with open(output_path, 'w') as f:
json.dump(export_data, f, indent=2)
return output_path
def export_to_excel(self, output_path: str) -> str:
"""Export all models summary to Excel."""
with pd.ExcelWriter(output_path, engine='openpyxl') as writer:
# Model comparison
comparison = self.compare_models()
comparison.to_excel(writer, sheet_name='Model Comparison', index=False)
# Feature importance for each model
for model_id in self.models:
importance = self.get_feature_importance(model_id)
sheet_name = f"Features_{model_id}"[:31]
importance.to_excel(writer, sheet_name=sheet_name, index=False)
return output_path
Quick Start
import pandas as pd
# Create builder
builder = MLModelBuilder("Office Projects")
# Sample training data
df = pd.DataFrame([
{'size_sf': 50000, 'floors': 10, 'complexity': 3, 'project_type': 'Office', 'duration': 365},
{'size_sf': 75000, 'floors': 15, 'complexity': 4, 'project_type': 'Office', 'duration': 450},
{'size_sf': 30000, 'floors': 5, 'complexity': 2, 'project_type': 'Office', 'duration': 280},
{'size_sf': 100000, 'floors': 20, 'complexity': 5, 'project_type': 'Office', 'duration': 520},
{'size_sf': 45000, 'floors': 8, 'complexity': 3, 'project_type': 'Office', 'duration': 340}
])
# Build model
model = builder.build_model(
df,
target_column='duration',
feature_columns=['size_sf', 'floors', 'complexity'],
target_type=PredictionTarget.DURATION,
algorithm=AlgorithmType.LINEAR_REGRESSION,
model_id='duration_model_v1'
)
print(f"R²: {model.metrics.r_squared}")
print(f"MAE: {model.metrics.mae} days")
# Make prediction
result = builder.predict('duration_model_v1', {
'size_sf': 60000,
'floors': 12,
'complexity': 3
})
print(f"Predicted duration: {result['prediction']} days")
Common Use Cases
1. Train Multiple Models
# Linear regression
linear_model = builder.build_model(df, 'cost', features,
PredictionTarget.COST, AlgorithmType.LINEAR_REGRESSION)
# Ridge regression
ridge_model = builder.build_model(df, 'cost', features,
PredictionTarget.COST, AlgorithmType.RIDGE_REGRESSION, alpha=1.0)
# k-NN
knn_model = builder.build_model(df, 'cost', features,
PredictionTarget.COST, AlgorithmType.KNN, k=5)
# Compare
comparison = builder.compare_models()
print(comparison)
2. Feature Importance
importance = builder.get_feature_importance('duration_model_v1')
print(importance)
3. Export Model
builder.export_model('duration_model_v1', 'model.json')
builder.export_to_excel('models_summary.xlsx')
Resources
- DDC Book: Chapter 4.5 - Future: Predictions and Machine Learning
- scikit-learn: https://scikit-learn.org/
- Website: https://datadrivenconstruction.io