hypergas.unit_conversion module#

Utility for converting between concentration/flux units that are all anchored to a common base unit: ppm (parts per million).

Supported units#

  • ‘ppm’ : parts per million (the reference/base unit)

  • ‘ppm m’ : ppm integrated over a path length in meters

  • ‘ppb’ : parts per billion

  • ‘umol m-2’ : micromoles per square meter

How it works#

Every unit is defined by a single number: the factor you multiply a ppm value by to express it in that unit (SCALE_FROM_PPM below). To convert between any two supported units, we simply:

  1. Convert the input value back to ppm (divide by its own factor).

  2. Convert that ppm value into the target unit (multiply by the target’s factor).

This means adding a new unit only requires adding one new entry to the SCALE_FROM_PPM dictionary — the conversion logic itself does not need to change.

Usage#

from unit_conversion import convert_units, get_scale_factor

# Convert a value directly value_ppb = convert_units(2.5, input_unit=’ppm’, output_unit=’ppb’)

# Or get the multiplicative factor and apply it yourself factor = get_scale_factor(input_unit=’ppm’, output_unit=’ppb’) value_ppb = 2.5 * factor

hypergas.unit_conversion.convert_units(value, input_unit, output_unit)[source]#

Convert value from input_unit to output_unit.

Parameters:

  • value (float or array-like) – The value(s) to convert. Works with plain numbers as well as numpy arrays / pandas Series, since it’s just a multiplication.

  • input_unit (str) – Unit that value is currently expressed in.

  • output_unit (str) – Unit to convert value into.

Returns:

float or array-like – value converted into output_unit.

Examples

>>> convert_units(2.5, 'ppm', 'ppb')
2500.0
>>> convert_units(2500, 'ppb', 'ppm')
2.5
hypergas.unit_conversion.get_scale_factor(input_unit, output_unit)[source]#

Compute the multiplicative factor to convert a value from input_unit to output_unit.

Both units must be keys in SCALE_FROM_PPM. Conversion always routes through ppm as the common base:

factor = SCALE_FROM_PPM[output_unit] / SCALE_FROM_PPM[input_unit]

Parameters:

  • input_unit (str) – Unit of the value you currently have (e.g. ‘ppm’, ‘ppb’).

  • output_unit (str) – Unit you want to convert to.

Returns:

float – Multiply your input value by this to get the output value.

Raises:

ValueError – If either unit is not in SCALE_FROM_PPM.

hypergas.unit_conversion.scale_from_ppm(units)[source]#

Return the factor to convert a value FROM ppm TO units.

Equivalent to the original _scale_units method, but as a standalone function. Prefer convert_units/get_scale_factor for new code, since they support arbitrary input/output unit pairs rather than assuming ppm as the input.