diff options
| -rw-r--r-- | CHANGELOG.md | 1 | ||||
| -rw-r--r-- | core/divelist.c | 74 | ||||
| -rw-r--r-- | core/planner.c | 2 |
3 files changed, 44 insertions, 33 deletions
diff --git a/CHANGELOG.md b/CHANGELOG.md index cc2e06a04..97309fe64 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,4 +1,5 @@ - mobile: add ability to edit tags +- Correct OTU and CNS calculations for planned bailout - replace dive computer management with a new implementation, this fixes rare cases where Subsurface unnecessarily download already downloaded dives, but also means that some older style dive computer can no longer have nicknames diff --git a/core/divelist.c b/core/divelist.c index 9beea4d7c..1d856118c 100644 --- a/core/divelist.c +++ b/core/divelist.c @@ -85,6 +85,35 @@ static int active_o2(const struct dive *dive, const struct divecomputer *dc, dur return get_o2(gas); } +// Do not call on first sample as it acccesses the previous sample +static int get_sample_o2(const struct dive *dive, const struct divecomputer *dc, const struct sample *sample) +{ + int po2i, po2f, po2; + const struct sample *psample = sample - 1; + // Use sensor[0] if available + if ((dc->divemode == CCR || dc->divemode == PSCR) && sample->o2sensor[0].mbar) { + po2i = psample->o2sensor[0].mbar; + po2f = sample->o2sensor[0].mbar; // then use data from the first o2 sensor + po2 = (po2f + po2i) / 2; + } else if (sample->setpoint.mbar > 0) { + po2 = MIN((int) sample->setpoint.mbar, + depth_to_mbar(sample->depth.mm, dive)); + } else { + double amb_presure = depth_to_bar(sample->depth.mm, dive); + double pamb_pressure = depth_to_bar(psample->depth.mm , dive); + if (dc->divemode == PSCR) { + po2i = pscr_o2(pamb_pressure, get_gasmix_at_time(dive, dc, psample->time)); + po2f = pscr_o2(amb_presure, get_gasmix_at_time(dive, dc, sample->time)); + } else { + int o2 = active_o2(dive, dc, psample->time); // ... calculate po2 from depth and FiO2. + po2i = lrint(o2 * pamb_pressure); // (initial) po2 at start of segment + po2f = lrint(o2 * amb_presure); // (final) po2 at end of segment + } + po2 = (po2i + po2f) / 2; + } + return po2; +} + /* Calculate OTU for a dive - this only takes the first divecomputer into account. Implement the protocol in Erik Baker's document "Oxygen Toxicity Calculations". This code implements a third-order continuous approximation of Baker's Eq. 2 and enables OTU @@ -104,15 +133,19 @@ static int calculate_otu(const struct dive *dive) struct sample *sample = dc->sample + i; struct sample *psample = sample - 1; t = sample->time.seconds - psample->time.seconds; - if ((dc->divemode == CCR || dc->divemode == PSCR) && sample->o2sensor[0].mbar) { // if dive computer has o2 sensor(s) (CCR & PSCR) .. + // if there is sensor data use sensor[0] + if ((dc->divemode == CCR || dc->divemode == PSCR) && sample->o2sensor[0].mbar) { po2i = psample->o2sensor[0].mbar; po2f = sample->o2sensor[0].mbar; // ... use data from the first o2 sensor } else { - if (dc->divemode == CCR) { - po2i = MIN((int) psample->setpoint.mbar, - depth_to_mbar(psample->depth.mm, dive)); // if CCR has no o2 sensors then use setpoint + if (sample->setpoint.mbar > 0) { po2f = MIN((int) sample->setpoint.mbar, depth_to_mbar(sample->depth.mm, dive)); + if (psample->setpoint.mbar > 0) + po2i = MIN((int) psample->setpoint.mbar, + depth_to_mbar(psample->depth.mm, dive)); + else + po2i = po2f; } else { // For OC and rebreather without o2 sensor/setpoint double amb_presure = depth_to_bar(sample->depth.mm, dive); double pamb_pressure = depth_to_bar(psample->depth.mm , dive); @@ -162,42 +195,17 @@ static double calculate_cns_dive(const struct dive *dive) /* Calculate the CNS for each sample in this dive and sum them */ for (n = 1; n < dc->samples; n++) { int t; - int po2i, po2f; - bool trueo2 = false; + int po2; struct sample *sample = dc->sample + n; struct sample *psample = sample - 1; t = sample->time.seconds - psample->time.seconds; - if ((dc->divemode == CCR || dc->divemode == PSCR) && sample->o2sensor[0].mbar) { // if dive computer has o2 sensor(s) (CCR & PSCR) - po2i = psample->o2sensor[0].mbar; - po2f = sample->o2sensor[0].mbar; // then use data from the first o2 sensor - trueo2 = true; - } - if ((dc->divemode == CCR) && (!trueo2)) { - po2i = MIN((int) psample->setpoint.mbar, - depth_to_mbar(psample->depth.mm, dive)); // if CCR has no o2 sensors then use setpoint - po2f = MIN((int) sample->setpoint.mbar, - depth_to_mbar(sample->depth.mm, dive)); - trueo2 = true; - } - if (!trueo2) { - double amb_presure = depth_to_bar(sample->depth.mm, dive); - double pamb_pressure = depth_to_bar(psample->depth.mm , dive); - if (dc->divemode == PSCR) { - po2i = pscr_o2(pamb_pressure, get_gasmix_at_time(dive, dc, psample->time)); - po2f = pscr_o2(amb_presure, get_gasmix_at_time(dive, dc, sample->time)); - } else { - int o2 = active_o2(dive, dc, psample->time); // ... calculate po2 from depth and FiO2. - po2i = lrint(o2 * pamb_pressure); // (initial) po2 at start of segment - po2f = lrint(o2 * amb_presure); // (final) po2 at end of segment - } - } - int po2avg = (po2i + po2f) / 2; // po2i now holds the mean po2 of initial and final po2 values of segment. + po2 = get_sample_o2(dive, dc, sample); /* Don't increase CNS when po2 below 500 matm */ - if (po2avg <= 500) + if (po2 <= 500) continue; // This formula is the result of fitting two lines to the Log of the NOAA CNS table - rate = po2i <= 1500 ? exp(-11.7853 + 0.00193873 * po2avg) : exp(-23.6349 + 0.00980829 * po2avg); + rate = po2 <= 1500 ? exp(-11.7853 + 0.00193873 * po2) : exp(-23.6349 + 0.00980829 * po2); cns += (double) t * rate * 100.0; } return cns; diff --git a/core/planner.c b/core/planner.c index 98c75df1e..598e568bf 100644 --- a/core/planner.c +++ b/core/planner.c @@ -284,6 +284,8 @@ static void create_dive_from_plan(struct diveplan *diveplan, struct dive *dive, } sample = prepare_sample(dc); sample[-1].setpoint.mbar = po2; + if (po2) + sample[-1].o2sensor[0].mbar = po2; sample->time.seconds = lasttime + 1; sample->depth = lastdepth; sample->manually_entered = dp->entered; |