Package kenozooid :: Package plan :: Module deco

Module deco

Decompression dive planning.

Classes
	DivePlanError Dive planner exception.
	GasList List of gas mixes.
	DivePlan Dive plan information.
	DiveProfile Dive profile information.
	ProfileType Dive profile type.

Functions

plan_deco_dive(plan, gas_list, depth, time)
Plan decompression dive.

source code

deco_stops(plan, profile)
Calculate decompression stops for a dive profile.

source code

dive_legs(profile, stops, descent_rate)
Calculate dive legs information.

source code

dive_legs_overhead(gas_list, legs)
Determine the overhead part of a decompression dive.

source code

dive_slate(profile, stops, legs, descent_rate)
Calculate dive slate for a dive profile.

source code

depth_to_time(start, end, rate)
Calculate time required to descent or ascent from start to end depth.

source code

sum_deco_time(legs)
Calculate total decompression time using dive legs.

source code

sum_dive_time(legs)
Calculate total dive time using dive legs.

source code

gas_vol_info(gas_vol, min_gas_vol)
Analyze gas volume requirements using gas mix volume calculations.

source code

gas_volume(gas_list, legs, rmv=20)
Calculate dive gas mix volume information.

source code

min_gas_volume(gas_list, legs, rmv=20)
Calculate minimal volume of gas mixes required for a dive using rule of thirds.

source code

gas_mix_depth_update(gas_list, ppo2, deco_ppo2)
Update gas mix list, so every gas mix has depth specified.

source code

plan_to_text(plan)
Convert decompression dive plan to text.

source code

parse_gas(t, travel=False)
Parse gas mix.

source code

parse_gas_list(*args)
Parse gas mix list.

source code

Variables
	logger = `logging.getLogger(__name__)`
	RE_GAS = `re.compile(...`

Function Details

plan_deco_dive(plan, gas_list, depth, time)

source code

Plan decompression dive.

The dive plan information is calculated and stored in the dive plan object.

Any dive plan configuration should be set in the dive plan object before calling this function.

Parameters:

plan - Dive plan object to be filled with dive plan information.
gas_list - Gas mix configuration list.
depth - Maximum dive depth.
time - Dive bottom time.

deco_stops(plan, profile)

source code

Calculate decompression stops for a dive profile.

The dive plan information is used to configure decompression engine.

Parameters:

plan - Dive plan information.
profile - Dive profile information.

dive_legs(profile, stops, descent_rate)

source code

Calculate dive legs information.

The dive legs information is used for other calculations, i.e. dive gas consumption, dive slate.

Dive profile is split into legs using

gas mix switch depths
dive maximum depth and bottom time
descent rate
list of decompression stops

The ascent rate is assumed to be 10m/min.

Each dive leg consists of the following information

start depth
end depth
time
gas mix used during a dive leg
deco zone indicator (true or false)

dive_legs_overhead(gas_list, legs)

source code


Determine the overhead part of a decompression dive.

The overhead part of a dive is the descent, bottom and ascent parts of
a dive up to first decompression stop or first decompression gas mix
switch.

The overhead part of a dive is used to calculate gas mix consumption
using rule of thirds.

:param gas_list: Gas list information.
:param legs: List of dive legs.

..seealso:: :py:func:`dive_legs`

dive_slate(profile, stops, legs, descent_rate)

source code

Calculate dive slate for a dive profile.

The dive decompression stops is a collection of items implementing the following interface

depth: Depth of dive stop [m].
time: Time of dive stop [min].

Dive slate is list of items consisting of

dive depth
decompression stop information, null if no decompression
run time in minutes
gas mix on gas switch, null otherwise

Parameters:

profile - Dive profile information.
stops - Dive decompression stops.
legs - Dive legs.
descent_rate - Dive descent rate.

depth_to_time(start, end, rate)

source code

Calculate time required to descent or ascent from start to end depth.

Parameters:

start - Starting depth.
end - Ending depth.
rate - Ascent or descent rate.

sum_deco_time(legs)

source code


Calculate total decompression time using dive legs.

:param legs: List of dive legs.

..seealso:: :py:func:`dive_legs`

sum_dive_time(legs)

source code


Calculate total dive time using dive legs.

:param legs: List of dive legs.

..seealso:: :py:func:`dive_legs`

gas_vol_info(gas_vol, min_gas_vol)

source code


Analyze gas volume requirements using gas mix volume calculations.

The list of messages is returned, which confirm required gas mix volume
or warn about gas logistics problems.

:param gas_vol: Gas volume requirements per gas mix.
:param min_gas_vol: Minimal gas mixes volume for the plan.

.. seealso::

   :py:func:`min_gas_volume`
   :py:func:`gas_volume`

gas_volume(gas_list, legs, rmv=20)

source code


Calculate dive gas mix volume information.

Gas mix volume is calculated for each gas mix on the gas list. The
volume information is returned as dictionary `gas mix name -> usage`,
where gas usage is volume of gas in liters.

The key of the gas mix volume dictionary is gas mix name to merge all
travel and decompression gas mixes information regardless their depth
switch.

FIXME: apply separate RMV for decompression gas

:param gas_list: Gas list information.
:param legs: List of dive legs.
:param rmv: Respiratory minute volume (RMV) [min/l].

..seealso:: :py:func:`dive_legs`

min_gas_volume(gas_list, legs, rmv=20)

source code

Calculate minimal volume of gas mixes required for a dive using rule of thirds.

The volume information is returned as dictionary gas mix -> usage, where gas usage is volume of gas in liters.

Parameters:

gas_list - Gas list information.
legs - List of dive legs.

gas_mix_depth_update(gas_list, ppo2, deco_ppo2)

source code

Update gas mix list, so every gas mix has depth specified.

The following rules are used

gas mixes with non-null depth are _not_ changed
first travel gas mix switch depth is 0m
if no travel gas mixes specified, then bottom gas mix switch depth is set to 0m
travel and bottom gas mixes are updated with MOD calculated using ppO2 and O2 value of previous gas mix on the list
decompression gas mixes are updated with MOD calculated using decompression ppO2 and O2 value of changed gas mix

Parameters:

gas_list - Gas mix list to modify.
ppo2 - ppO2 value used to calculate MOD of travel and bottom gas mixes.
deco_ppo2 - ppO2 value used to calculate MOD of decompression gas mixes.

parse_gas(t, travel=False)

source code

Parse gas mix.

Parameters:

t - Gas mix string.
travel - True if travel gas mix.

parse_gas_list(*args)

source code

Parse gas mix list.

Parameters:

*args - List of gas mix strings.

Variables Details

RE_GAS

Value:

re.compile("""
    ^(?P<name>
        (?P<type> O2 | AIR | EAN | TX)
        ((?<=TX|AN)(?P<o2>[0-9]{2}))?
        ((?<=TX..)/(?P<he>[0-9]{2}))?
    )
    (@(?P<depth>[0-9]+))?
    (\|(?P<tank>([2-9]x[1-9]{1,2})))?
...