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First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
/* calculate deco values
* based on Bühlmann ZHL-16b
* based on an implemention by heinrichs weikamp for the DR5
* the original file doesn't carry a license and is used here with
* the permission of Matthias Heinrichs
*
* The implementation below is (C) Dirk Hohndel 2012 and released under the GPLv2
*
* clear_deco() - call to initialize for a new deco calculation
Consider previous dives when calculating deco This also initializes the N2 tissue saturations to correct numbers (setting them to zero was clearly silly). With this commit we walk back in the dive_table until we find a surface intervall that's longer than 48h. Or a dive that comes after the last one we looked at; that would indicate that this is a divelist that contains dives from multiple divers or dives that for other reasons are not ordered. In a sane environment one would assume that the dives that need to be taken into account when doing deco calculations are organized as one trip in the XML file and so this logic should work. One major downside of the current implementation is that we recalculate everything whenever the plot_info is recreated - which happens quite frequently, for example when resizing the window or even when we go into loup mode. While this isn't all that compute intensive, this is an utter waste and we should at least cache the saturation inherited from previous dives (and clear that number when the selected dive changes). We don't want to cache all of it as the recreation of the plot_info may be triggered by the user changing equipment (and most importantly, gasmix) information. In that case the deco data for this dive does indeed have to be recreated. But without changing the current dive the saturation after the last surface intervall should stay the same. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 04:45:20 +00:00
* add_segment(pressure, gasmix, seconds) - add <seconds> at the given pressure, breathing gasmix
Use gradient factors in deco calculation Usually dive computers show the ceiling in terms of the next deco stop - and those are in 3m increments. This commit also adds the ability to chose either the typical 3m increments or the smooth ceiling that the Bühlmann algorithm actually calculates. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 07:22:07 +00:00
* deco_allowed_depth(tissues_tolerance, surface_pressure, dive, smooth)
* - ceiling based on lead tissue, surface pressure, 3m increments or smooth
Make GF values configurable There are a couple of issues with this commit: GtkEntry should emit the 'changed' signal when it is modified (so that changes in the preferences get applied right away) - but that doesn't appear to be working consistently. Also, this doesn't appear to affect the deco of any dives that I try it with. So my guess is something is wrong with the underlying deco algorithm. That's diappointing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 05:31:22 +00:00
* set_gf(gflow, gfhigh) - set Buehlmann gradient factors
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
*/
Consider previous dives when calculating deco This also initializes the N2 tissue saturations to correct numbers (setting them to zero was clearly silly). With this commit we walk back in the dive_table until we find a surface intervall that's longer than 48h. Or a dive that comes after the last one we looked at; that would indicate that this is a divelist that contains dives from multiple divers or dives that for other reasons are not ordered. In a sane environment one would assume that the dives that need to be taken into account when doing deco calculations are organized as one trip in the XML file and so this logic should work. One major downside of the current implementation is that we recalculate everything whenever the plot_info is recreated - which happens quite frequently, for example when resizing the window or even when we go into loup mode. While this isn't all that compute intensive, this is an utter waste and we should at least cache the saturation inherited from previous dives (and clear that number when the selected dive changes). We don't want to cache all of it as the recreation of the plot_info may be triggered by the user changing equipment (and most importantly, gasmix) information. In that case the deco data for this dive does indeed have to be recreated. But without changing the current dive the saturation after the last surface intervall should stay the same. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 04:45:20 +00:00
#include <math.h>
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
#include "dive.h"
//! Option structure for Buehlmann decompression.
struct buehlmann_config {
double satmult; //! safety at inert gas accumulation as percentage of effect (more than 100).
double desatmult; //! safety at inert gas depletion as percentage of effect (less than 100).
double safety_dist_deco_stop;//! assumed distance to official decompression where decompression takes places.
int last_deco_stop_in_mtr; //! depth of last_deco_stop.
double gf_high; //! gradient factor high (at surface).
double gf_low; //! gradient factor low (at bottom/start of deco calculation).
double gf_low_position_min; //! gf_low_position below surface_min_shallow.
double gf_low_position_max; //! gf_low_position below surface_max_depth.
double gf_high_emergency; //! emergency gf factors
double gf_low_emergency; //! gradient factor low (at bottom/start of deco calculation).
};
Use gradient factors in deco calculation Usually dive computers show the ceiling in terms of the next deco stop - and those are in 3m increments. This commit also adds the ability to chose either the typical 3m increments or the smooth ceiling that the Bühlmann algorithm actually calculates. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 07:22:07 +00:00
struct buehlmann_config buehlmann_config = { 1.0, 1.01, 0.5, 3, 75.0, 35.0, 10.0, 30.0, 95.0, 95.0 };
struct dive_data {
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
double pressure; //! pesent ambient pressure
double surface; //! pressure at water surface
struct gasmix *gasmix; //! current selected gas
};
const double buehlmann_N2_a[] = {1.1696, 1.0, 0.8618, 0.7562,
0.62, 0.5043, 0.441, 0.4,
0.375, 0.35, 0.3295, 0.3065,
0.2835, 0.261, 0.248, 0.2327};
const double buehlmann_N2_b[] = {0.5578, 0.6514, 0.7222, 0.7825,
0.8126, 0.8434, 0.8693, 0.8910,
0.9092, 0.9222, 0.9319, 0.9403,
0.9477, 0.9544, 0.9602, 0.9653};
const double buehlmann_N2_t_halflife[] = {5.0, 8.0, 12.5, 18.5,
27.0, 38.3, 54.3, 77.0,
109.0, 146.0, 187.0, 239.0,
305.0, 390.0, 498.0, 635.0};
const double buehlmann_N2_factor_expositon_one_second[] = {
2.30782347297664E-003, 1.44301447809736E-003, 9.23769302935806E-004, 6.24261986779007E-004,
4.27777107246730E-004, 3.01585140931371E-004, 2.12729727268379E-004, 1.50020603047807E-004,
1.05980191127841E-004, 7.91232600646508E-005, 6.17759153688224E-005, 4.83354552742732E-005,
3.78761777920511E-005, 2.96212356654113E-005, 2.31974277413727E-005, 1.81926738960225E-005};
const double buehlmann_He_a[] = { 1.6189, 1.383 , 1.1919, 1.0458,
0.922 , 0.8205, 0.7305, 0.6502,
0.595 , 0.5545, 0.5333, 0.5189,
0.5181, 0.5176, 0.5172, 0.5119};
const double buehlmann_He_b[] = {0.4770, 0.5747, 0.6527, 0.7223,
0.7582, 0.7957, 0.8279, 0.8553,
0.8757, 0.8903, 0.8997, 0.9073,
0.9122, 0.9171, 0.9217, 0.9267};
const double buehlmann_He_t_halflife[] = {1.88, 3.02, 4.72, 6.99,
10.21, 14.48, 20.53, 29.11,
41.20, 55.19, 70.69, 90.34,
115.29, 147.42, 188.24, 240.03};
const double buehlmann_He_factor_expositon_one_second[] = {
6.12608039419837E-003, 3.81800836683133E-003, 2.44456078654209E-003, 1.65134647076792E-003,
1.13084424730725E-003, 7.97503165599123E-004, 5.62552521860549E-004, 3.96776399429366E-004,
2.80360036664540E-004, 2.09299583354805E-004, 1.63410794820518E-004, 1.27869320250551E-004,
1.00198406028040E-004, 7.83611475491108E-005, 6.13689891868496E-005, 4.81280465299827E-005};
#define WV_PRESSURE 0.0627 /* water vapor pressure */
Consider previous dives when calculating deco This also initializes the N2 tissue saturations to correct numbers (setting them to zero was clearly silly). With this commit we walk back in the dive_table until we find a surface intervall that's longer than 48h. Or a dive that comes after the last one we looked at; that would indicate that this is a divelist that contains dives from multiple divers or dives that for other reasons are not ordered. In a sane environment one would assume that the dives that need to be taken into account when doing deco calculations are organized as one trip in the XML file and so this logic should work. One major downside of the current implementation is that we recalculate everything whenever the plot_info is recreated - which happens quite frequently, for example when resizing the window or even when we go into loup mode. While this isn't all that compute intensive, this is an utter waste and we should at least cache the saturation inherited from previous dives (and clear that number when the selected dive changes). We don't want to cache all of it as the recreation of the plot_info may be triggered by the user changing equipment (and most importantly, gasmix) information. In that case the deco data for this dive does indeed have to be recreated. But without changing the current dive the saturation after the last surface intervall should stay the same. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 04:45:20 +00:00
#define N2_IN_AIR 0.7902
Use gradient factors in deco calculation Usually dive computers show the ceiling in terms of the next deco stop - and those are in 3m increments. This commit also adds the ability to chose either the typical 3m increments or the smooth ceiling that the Bühlmann algorithm actually calculates. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 07:22:07 +00:00
#define DIST_FROM_3_MTR 0.28
#define PRESSURE_CHANGE_3M 0.3
#define TOLERANCE 0.02
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
double tissue_n2_sat[16];
double tissue_he_sat[16];
double tissue_tolerated_ambient_pressure[16];
int ci_pointing_to_guiding_tissue;
Use gradient factors in deco calculation Usually dive computers show the ceiling in terms of the next deco stop - and those are in 3m increments. This commit also adds the ability to chose either the typical 3m increments or the smooth ceiling that the Bühlmann algorithm actually calculates. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 07:22:07 +00:00
double gf_low_position_this_dive;
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
int divetime;
Use gradient factors in deco calculation Usually dive computers show the ceiling in terms of the next deco stop - and those are in 3m increments. This commit also adds the ability to chose either the typical 3m increments or the smooth ceiling that the Bühlmann algorithm actually calculates. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 07:22:07 +00:00
static double actual_gradient_limit(const struct dive_data *data)
{
double pressure_diff, limit_at_position;
double gf_high = buehlmann_config.gf_high;
double gf_low = buehlmann_config.gf_low;
pressure_diff = data->pressure - data->surface;
if (pressure_diff > TOLERANCE) {
if (pressure_diff < gf_low_position_this_dive)
limit_at_position = gf_high - ((gf_high - gf_low) * pressure_diff / gf_low_position_this_dive);
else
limit_at_position = gf_low;
} else {
limit_at_position = gf_high;
}
return limit_at_position;
}
static double gradient_factor_calculation(const struct dive_data *data)
{
double tissue_inertgas_saturation;
tissue_inertgas_saturation = tissue_n2_sat[ci_pointing_to_guiding_tissue] +
tissue_he_sat[ci_pointing_to_guiding_tissue];
if (tissue_inertgas_saturation < data->pressure)
return 0.0;
else
return (tissue_inertgas_saturation - data->pressure) /
(tissue_inertgas_saturation - tissue_tolerated_ambient_pressure[ci_pointing_to_guiding_tissue]);
}
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
static double tissue_tolerance_calc(void)
{
int ci = -1;
double tissue_inertgas_saturation, buehlmann_inertgas_a, buehlmann_inertgas_b;
double ret_tolerance_limit_ambient_pressure = -1.0;
for (ci = 0; ci < 16; ci++)
{
tissue_inertgas_saturation = tissue_n2_sat[ci] + tissue_he_sat[ci];
buehlmann_inertgas_a = ((buehlmann_N2_a[ci] * tissue_n2_sat[ci]) + (buehlmann_He_a[ci] * tissue_he_sat[ci])) / tissue_inertgas_saturation;
buehlmann_inertgas_b = ((buehlmann_N2_b[ci] * tissue_n2_sat[ci]) + (buehlmann_He_b[ci] * tissue_he_sat[ci])) / tissue_inertgas_saturation;
tissue_tolerated_ambient_pressure[ci] = (tissue_inertgas_saturation - buehlmann_inertgas_a) * buehlmann_inertgas_b;
if (tissue_tolerated_ambient_pressure[ci] > ret_tolerance_limit_ambient_pressure)
{
ci_pointing_to_guiding_tissue = ci;
ret_tolerance_limit_ambient_pressure = tissue_tolerated_ambient_pressure[ci];
}
}
return (ret_tolerance_limit_ambient_pressure);
}
/* add a second at the given pressure and gas to the deco calculation */
Consider previous dives when calculating deco This also initializes the N2 tissue saturations to correct numbers (setting them to zero was clearly silly). With this commit we walk back in the dive_table until we find a surface intervall that's longer than 48h. Or a dive that comes after the last one we looked at; that would indicate that this is a divelist that contains dives from multiple divers or dives that for other reasons are not ordered. In a sane environment one would assume that the dives that need to be taken into account when doing deco calculations are organized as one trip in the XML file and so this logic should work. One major downside of the current implementation is that we recalculate everything whenever the plot_info is recreated - which happens quite frequently, for example when resizing the window or even when we go into loup mode. While this isn't all that compute intensive, this is an utter waste and we should at least cache the saturation inherited from previous dives (and clear that number when the selected dive changes). We don't want to cache all of it as the recreation of the plot_info may be triggered by the user changing equipment (and most importantly, gasmix) information. In that case the deco data for this dive does indeed have to be recreated. But without changing the current dive the saturation after the last surface intervall should stay the same. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 04:45:20 +00:00
double add_segment(double pressure, struct gasmix *gasmix, int period_in_seconds)
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
{
int ci;
double ppn2 = (pressure - WV_PRESSURE) * (1000 - gasmix->o2.permille - gasmix->he.permille) / 1000.0;
double pphe = (pressure - WV_PRESSURE) * gasmix->he.permille / 1000.0;
/* right now we just do OC */
Consider previous dives when calculating deco This also initializes the N2 tissue saturations to correct numbers (setting them to zero was clearly silly). With this commit we walk back in the dive_table until we find a surface intervall that's longer than 48h. Or a dive that comes after the last one we looked at; that would indicate that this is a divelist that contains dives from multiple divers or dives that for other reasons are not ordered. In a sane environment one would assume that the dives that need to be taken into account when doing deco calculations are organized as one trip in the XML file and so this logic should work. One major downside of the current implementation is that we recalculate everything whenever the plot_info is recreated - which happens quite frequently, for example when resizing the window or even when we go into loup mode. While this isn't all that compute intensive, this is an utter waste and we should at least cache the saturation inherited from previous dives (and clear that number when the selected dive changes). We don't want to cache all of it as the recreation of the plot_info may be triggered by the user changing equipment (and most importantly, gasmix) information. In that case the deco data for this dive does indeed have to be recreated. But without changing the current dive the saturation after the last surface intervall should stay the same. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 04:45:20 +00:00
if (period_in_seconds == 1) { /* that's what we do during the dive */
for (ci = 0; ci < 16; ci++) {
if (ppn2 - tissue_n2_sat[ci] > 0)
tissue_n2_sat[ci] += buehlmann_config.satmult * (ppn2 - tissue_n2_sat[ci]) *
buehlmann_N2_factor_expositon_one_second[ci];
else
tissue_n2_sat[ci] += buehlmann_config.desatmult * (ppn2 - tissue_n2_sat[ci]) *
buehlmann_N2_factor_expositon_one_second[ci];
if (pphe - tissue_he_sat[ci] > 0)
tissue_he_sat[ci] += buehlmann_config.satmult * (pphe - tissue_he_sat[ci]) *
buehlmann_He_factor_expositon_one_second[ci];
else
tissue_he_sat[ci] += buehlmann_config.desatmult * (pphe - tissue_he_sat[ci]) *
buehlmann_He_factor_expositon_one_second[ci];
}
} else { /* all other durations */
for (ci = 0; ci < 16; ci++)
{
if (ppn2 - tissue_n2_sat[ci] > 0)
tissue_n2_sat[ci] += buehlmann_config.satmult * (ppn2 - tissue_n2_sat[ci]) *
(1 - pow(2.0,(- period_in_seconds / (buehlmann_N2_t_halflife[ci] * 60))));
else
tissue_n2_sat[ci] += buehlmann_config.desatmult * (ppn2 - tissue_n2_sat[ci]) *
(1 - pow(2.0,(- period_in_seconds / (buehlmann_N2_t_halflife[ci] * 60))));
if (pphe - tissue_he_sat[ci] > 0)
tissue_he_sat[ci] += buehlmann_config.satmult * (pphe - tissue_he_sat[ci]) *
(1 - pow(2.0,(- period_in_seconds / (buehlmann_He_t_halflife[ci] * 60))));
else
tissue_he_sat[ci] += buehlmann_config.desatmult * (pphe - tissue_he_sat[ci]) *
(1 - pow(2.0,(- period_in_seconds / (buehlmann_He_t_halflife[ci] * 60))));
}
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
}
return tissue_tolerance_calc();
}
Consider previous dives when calculating deco This also initializes the N2 tissue saturations to correct numbers (setting them to zero was clearly silly). With this commit we walk back in the dive_table until we find a surface intervall that's longer than 48h. Or a dive that comes after the last one we looked at; that would indicate that this is a divelist that contains dives from multiple divers or dives that for other reasons are not ordered. In a sane environment one would assume that the dives that need to be taken into account when doing deco calculations are organized as one trip in the XML file and so this logic should work. One major downside of the current implementation is that we recalculate everything whenever the plot_info is recreated - which happens quite frequently, for example when resizing the window or even when we go into loup mode. While this isn't all that compute intensive, this is an utter waste and we should at least cache the saturation inherited from previous dives (and clear that number when the selected dive changes). We don't want to cache all of it as the recreation of the plot_info may be triggered by the user changing equipment (and most importantly, gasmix) information. In that case the deco data for this dive does indeed have to be recreated. But without changing the current dive the saturation after the last surface intervall should stay the same. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 04:45:20 +00:00
void dump_tissues()
{
int ci;
printf("N2 tissues:");
for (ci = 0; ci < 16; ci++)
printf(" %6.3e", tissue_n2_sat[ci]);
printf("\nHe tissues:");
for (ci = 0; ci < 16; ci++)
printf(" %6.3e", tissue_he_sat[ci]);
printf("\n");
}
void clear_deco(double surface_pressure)
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
{
int ci;
for (ci = 0; ci < 16; ci++) {
Consider previous dives when calculating deco This also initializes the N2 tissue saturations to correct numbers (setting them to zero was clearly silly). With this commit we walk back in the dive_table until we find a surface intervall that's longer than 48h. Or a dive that comes after the last one we looked at; that would indicate that this is a divelist that contains dives from multiple divers or dives that for other reasons are not ordered. In a sane environment one would assume that the dives that need to be taken into account when doing deco calculations are organized as one trip in the XML file and so this logic should work. One major downside of the current implementation is that we recalculate everything whenever the plot_info is recreated - which happens quite frequently, for example when resizing the window or even when we go into loup mode. While this isn't all that compute intensive, this is an utter waste and we should at least cache the saturation inherited from previous dives (and clear that number when the selected dive changes). We don't want to cache all of it as the recreation of the plot_info may be triggered by the user changing equipment (and most importantly, gasmix) information. In that case the deco data for this dive does indeed have to be recreated. But without changing the current dive the saturation after the last surface intervall should stay the same. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 04:45:20 +00:00
tissue_n2_sat[ci] = (surface_pressure - WV_PRESSURE) * N2_IN_AIR;
First stab at deco calculations This seems to give us roughly the right data but needs a lot more testing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 05:21:36 +00:00
tissue_he_sat[ci] = 0.0;
tissue_tolerated_ambient_pressure[ci] = 0.0;
}
divetime = 0;
}
Use gradient factors in deco calculation Usually dive computers show the ceiling in terms of the next deco stop - and those are in 3m increments. This commit also adds the ability to chose either the typical 3m increments or the smooth ceiling that the Bühlmann algorithm actually calculates. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-03 07:22:07 +00:00
unsigned int deco_allowed_depth(double tissues_tolerance, double surface_pressure, struct dive *dive, gboolean smooth)
{
unsigned int depth, multiples_of_3m;
gboolean below_gradient_limit;
double new_gradient_factor;
double pressure_delta = tissues_tolerance - surface_pressure;
struct dive_data mydata;
if (pressure_delta > 0) {
if (!smooth) {
multiples_of_3m = (pressure_delta + DIST_FROM_3_MTR) / 0.3;
depth = 3000 * multiples_of_3m;
} else {
depth = rel_mbar_to_depth(pressure_delta * 1000, dive);
}
} else {
depth = 0;
}
mydata.pressure = surface_pressure + depth / 10000.0;
mydata.surface = surface_pressure;
new_gradient_factor = gradient_factor_calculation(&mydata);
below_gradient_limit = (new_gradient_factor < actual_gradient_limit(&mydata));
while(!below_gradient_limit)
{
mydata.pressure += PRESSURE_CHANGE_3M;
new_gradient_factor = gradient_factor_calculation(&mydata);
below_gradient_limit = (new_gradient_factor < actual_gradient_limit(&mydata));
}
return depth;
}
Make GF values configurable There are a couple of issues with this commit: GtkEntry should emit the 'changed' signal when it is modified (so that changes in the preferences get applied right away) - but that doesn't appear to be working consistently. Also, this doesn't appear to affect the deco of any dives that I try it with. So my guess is something is wrong with the underlying deco algorithm. That's diappointing. Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
2013-01-04 05:31:22 +00:00
void set_gf(double gflow, double gfhigh)
{
if (gflow != -1.0)
buehlmann_config.gf_low = gflow;
if (gfhigh != -1.0)
buehlmann_config.gf_high = gfhigh;
}
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