Simplifies a quantity with units using sympy's built-in simplify method for Quantity objects.
Args:
expr_key: The key of the expression (previously introduced) to simplify.
unit_system: Optional unit system (from UnitSystem enum). Not used with direct simplify method.
The following units are available by default:
SI base units: meter, second, kilogram, ampere, kelvin, mole, candela
Length: kilometer, millimeter
Mass: gram
Energy: joule
Force: newton
Pressure: pascal
Power: watt
Electric: coulomb, volt, ohm, farad, henry
Constants: speed_of_light, gravitational_constant, planck
Example:
# Simplify force expressed in base units
expr_key = introduce_expression("kilogram*meter/second**2")
result = quantity_simplify_units(expr_key)
# Returns newton (as N = kg·m/s²)
# Simplify a complex expression with mixed units
expr_key = introduce_expression("joule/(kilogram*meter**2/second**2)")
result = quantity_simplify_units(expr_key)
# Returns a dimensionless quantity (1)
# Simplify electrical power expression
expr_key = introduce_expression("volt*ampere")
result = quantity_simplify_units(expr_key)
# Returns watt
Example with Speed of Light:
# Introduce the speed of light
c_key = introduce_expression("speed_of_light")
# Convert to kilometers per hour
km_per_hour_key = convert_to_units(c_key, ["kilometer", "1/hour"])
# Simplify to get the numerical value
simplified_key = quantity_simplify_units(km_per_hour_key)
# Print the result
print_latex_expression(simplified_key)
# Shows the numeric value of speed of light in km/h
Returns:
A key for the simplified expression, or an error message.