# Environment Error
**URL:** https://discourse.kitware.com/t/environment-error/519
**Category:** Pulse Physiology Engine
**Created:** [August 3, 2020, 11:59pm UTC](https://discourse.kitware.com/t/environment-error/519 "2020-08-03T23:59:48Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@lyh](https://discourse.kitware.com/u/lyh)
#### Post date: [August 3, 2020, 11:59pm UTC](https://discourse.kitware.com/t/environment-error/519/1 "2020-08-03T23:59:48Z")
[INFO] : [8.56(s)] [Action] 8.56(s), Environment Action : Change Environmental Conditions
SurroundingType: NullSurrounding
Air Velocity: 0.1(m/s)
Ambient Temperature: 22(degC)
Atmospheric Pressure: Not Set
Clothing Resistance: 0.5(clo)
Emissivity: 0.95
Mean Radiant Temperature: 22(degC)
Relative Humidity: 0.6
Respiration Ambient Temperature: 22(degC)
Substance : Nitrogen Fraction Amount 0.7896
Substance : Oxygen Fraction Amount 0.21
Substance : CarbonDioxide Fraction Amount 0.0004
Substance : CarbonMonoxide Fraction Amount 0
[ERROR] : [8.56(s)] Environment Ambient Substance fractions do not sum to 1
[INFO] : [102.62(s)] [Action] 102.62(s), Environment Action : Change Environmental Conditions
SurroundingType: NullSurrounding
Air Velocity: 0.1(m/s)
Ambient Temperature: 22(degC)
Atmospheric Pressure: Not Set
Clothing Resistance: 0.5(clo)
Emissivity: 0.95
Mean Radiant Temperature: 22(degC)
Relative Humidity: 0.6
Respiration Ambient Temperature: 22(degC)
Substance : Nitrogen Fraction Amount 0.7896
Substance : Oxygen Fraction Amount 0.21
Substance : CarbonDioxide Fraction Amount 0.0003
Substance : CarbonMonoxide Fraction Amount 0.0001
[ERROR] : [102.62(s)] Environment Ambient Substance fractions do not sum to 1
---
### Author:  [@lyh](https://discourse.kitware.com/u/lyh)
#### Post date: [August 4, 2020, 2:41am UTC](https://discourse.kitware.com/t/environment-error/519/2 "2020-08-04T02:41:58Z")
conditions.GetAmbientGas(\*N2).GetFractionAmount().SetValue(0.7896);
conditions.GetAmbientGas(\*O2).GetFractionAmount().SetValue(0.21);
conditions.GetAmbientGas(\*CO2).GetFractionAmount().SetValue( 0.0003);
conditions.GetAmbientGas(\*CO).GetFractionAmount().SetValue( 0.0001);
**after that**
**In another thread**
pe-\>ProcessAction(env);
**Cause error**
---
### Author:  [@abray](https://discourse.kitware.com/u/abray)
#### Post date: [August 4, 2020, 3:00am UTC](https://discourse.kitware.com/t/environment-error/519/3 "2020-08-04T03:00:11Z")
I ran the HowTo-EvironmentChange and modified [these lines](https://gitlab.kitware.com/physiology/engine/-/blob/master/src/cpp/howto/HowTo-EnvironmentChange.cpp#L127) to match your numbers
I did not get the error.
You can test the specific method by doing
double n2 = 0.7896;
double o2 = 0.21;
double co2 = 0.0003;
double co = 0.0001;
double total = n2 + o2 + co2 + co;
if (!SEScalar::IsValue(1, total))
std::cout \<\< “Not One” \<\< std::endl;
On my machine total = 0.99999999999999989;
But this is with in the 1e-10 epsilon used by [IsValue](https://gitlab.kitware.com/physiology/engine/-/blob/master/src/cpp/cdm/properties/SEScalar.cpp#L231)