engineering-context-init - SKILL.md Agent Skill

name: engineering-context-init description: "Initialize engineering session with standard constants, units, and imports" category: helpers domain: general complexity: basic dependencies: - numpy - pint - scipy - matplotlib

Engineering Context Initialization Helper

Purpose

Standardize engineering sessions with a consistent environment that includes:

Standard physical constants
Unit registry for dimensional analysis
Common scientific computing libraries
Default plotting configurations
Precision settings for numerical calculations

This helper eliminates the need to repeatedly set up the same environment at the start of each engineering session, ensuring consistency and saving time.

What It Sets Up

Standard Constants

g: Standard gravity (9.80665 m/s²)
R: Universal gas constant (8.314462618 J/(mol·K))
R_air: Specific gas constant for air (287.05 J/(kg·K))
gamma_air: Specific heat ratio for air (1.4)
P_atm: Standard atmospheric pressure (101325 Pa)
T_std: Standard temperature (288.15 K / 15°C)
rho_air_std: Standard air density (1.225 kg/m³)
mu_air_std: Dynamic viscosity of air at standard conditions (1.789e-5 Pa·s)
nu_air_std: Kinematic viscosity of air at standard conditions (1.460e-5 m²/s)
c_light: Speed of light (299792458 m/s)
sigma_sb: Stefan-Boltzmann constant (5.670374419e-8 W/(m²·K⁴))

Unit Registry (Pint)

Configured pint UnitRegistry for dimensional analysis
Support for unit conversions
Unit-aware calculations

Common Imports

NumPy: Array operations and mathematical functions
SciPy: Scientific computing (optimize, integrate, interpolate, special functions)
Matplotlib: Plotting and visualization
Pandas: Data manipulation (optional, if available)

Default Plotting Style

Figure size: 10x6 inches
Grid enabled
LaTeX-style font rendering (if available)
Professional color schemes

Precision Settings

NumPy print precision: 6 decimal places
Print suppression for small values
Consistent formatting across sessions

Usage

Quick Start

Simply run the initialization script at the start of your session:

exec(open('init-script.py').read())

Or copy-paste the contents of init-script.py directly into your Python session.

Example 1: Basic Calculations with Units

# After running init-script.py
from pint import UnitRegistry
ureg = UnitRegistry()

# Define a pressure with units
pressure = 500 * ureg.kPa
print(f"Pressure: {pressure}")
print(f"Pressure in psi: {pressure.to('psi')}")

# Calculate ideal gas properties
T = 300 * ureg.kelvin
V = 2 * ureg.m**3
n = (pressure * V / (R * T)).to('mol')
print(f"Moles of gas: {n:.2f}")

Example 2: Atmospheric Calculations

# After running init-script.py

# Calculate density at altitude using standard constants
altitude = 5000  # meters
T = T_std - 0.0065 * altitude  # Temperature lapse rate
P = P_atm * (T / T_std) ** (g / (0.0065 * R_air))
rho = P / (R_air * T)

print(f"At {altitude}m altitude:")
print(f"Temperature: {T:.2f} K ({T-273.15:.2f} °C)")
print(f"Pressure: {P:.2f} Pa ({P/1000:.2f} kPa)")
print(f"Density: {rho:.4f} kg/m³")

Example 3: Flow Calculations

# After running init-script.py

# Reynolds number calculation
velocity = 50  # m/s
length = 2     # m characteristic length
Re = velocity * length / nu_air_std

print(f"Reynolds number: {Re:.2e}")
if Re > 5e5:
    print("Flow is turbulent")
else:
    print("Flow is laminar")

Example 4: Quick Plotting

# After running init-script.py
import numpy as np
import matplotlib.pyplot as plt

# The plotting style is already configured
x = np.linspace(0, 2*np.pi, 100)
y = np.sin(x)

plt.figure()
plt.plot(x, y, linewidth=2)
plt.xlabel('x [rad]')
plt.ylabel('sin(x)')
plt.title('Example Plot with Pre-configured Style')
plt.show()

Example 5: Unit Conversions

# After running init-script.py

# Power calculation with unit conversions
force = 1000 * ureg.N
velocity = 30 * ureg.m / ureg.s
power = (force * velocity).to('kW')

print(f"Power: {power}")
print(f"Power in hp: {power.to('hp'):.2f}")
print(f"Power in BTU/hr: {power.to('BTU/hr'):.2f}")

Files Included

SKILL.md: This documentation file
init-script.py: Complete initialization script ready to run
constants.md: Reference list of all constants and their values

Notes

The script checks for library availability and imports only what's available
If matplotlib is not available, plotting configuration is skipped
If pandas is not available, it's simply not imported (optional)
All constants use SI units unless otherwise specified
The pint UnitRegistry is created as ureg for unit-aware calculations

Customization

You can modify init-script.py to:

Add domain-specific constants
Change default plotting styles
Adjust precision settings
Include additional library imports
Set up custom unit definitions in pint

Best Practices

Run the initialization at the start of each new engineering session
Keep the script updated with your most commonly used constants
Document any custom constants you add
Use the unit registry for all calculations involving physical quantities
Store the script in your project directory for easy access