tests1_low.R
In biogas: Process Biogas Data and Predict Biogas Production

# test values form the lower level functions

# NTS No test yet for rbindf.R and partCO2.R

# volume molar values:
vmch4 <- 22360.588
vmco2 <- 22263.009

# Functions test with no dependencies 
#------------------------------------

# interp.R
# NTS maybe need more test here on error messages
expect_equal(interp(c(1, 3 , 4), y = c(1, 3, 4), time.out = 2), c(t2 = 2))
expect_equal(interp(c(1, 3 , 4), y = c(1, 3, 4), time.out = 0, extrap = TRUE), c(t0 = 1))
expect_equal(interp(c(1, 3 , 4), y = c(1, 3, 4), time.out = 0, extrap = TRUE, method = 'hyman'), c(t0 = 0))
  
# unitConvert.R
# NTS can be improved with more tests for each units
expect_equal(biogas:::unitConvert(1, 'atm', to = 'Pa'), 101325)
expect_equal(biogas:::unitConvert(0, 'C', to = 'K'), 273.15)

# readFormula.R
# readFormula reads correctly the formulas independement from case sensitivity and double letter elements
expect_equal(biogas:::readFormula('c6h12o6'), c(c = 6, h = 12, o = 6))
expect_equal(biogas:::readFormula('C6H12O6'), c(C = 6, H = 12, O = 6))
expect_equal(biogas:::readFormula('NaCl'), c(Na = 1, Cl = 1))
expect_equal(biogas:::readFormula('CHONNaClSPK'), c(C = 1, H = 1, O = 1, N = 1, Na = 1, Cl = 1, S = 1, P = 1, K = 1))

# watVap.R
# results from watVap is stable
# water vapor at 20 C, 1 atm 
temp.c <- 20
wV <- 100*6.1094*exp(17.625*temp.c/(243.04 + temp.c))
expect_equal(biogas:::watVap(293.15),wV)

# Functions test with dependencies 
#------------------------------------

# molMass.R -- depends on readFormula
# molMass results with one letter element are correct
mmcellu <- 12.01*6 + 1.008*12 + 16.00*6
expect_equal(molMass('C6H12O6'), mmcellu, tolerance = 0.01)
  
# molMass results are not influencend by case sensitivity
expect_equal(molMass('c6h12o6'), molMass('C6H12O6'))

# molMass results is correct for non organic formula - two letter elements
mmNaCl <- 22.990 + 35.45
expect_equal(molMass('NaCl'), mmNaCl, tolerance = 0.01)
  
# molMass result is correct for formula mixing one and two letter elements
mm <-  12.01 + 1.008 + 16.00 + 14.007 + 32.06 + 30.974 + 22.990 + 39.098 + 35.45
expect_equal(molMass('CHONNaClSPK'), mm, tolerance = 0.01)

# molMass result is correct for formula with parentheses
expect_equal(molMass('FeSO4(H2O)7'), 278.0146, tolerance = 0.01)

# calcCOD.R -- depends on molMass , readFormula 
# Not sure if the best approach here. molmass cellu as hard value or calculated with molmass
# calcCOD results with one letter elelement are correct 
CODcellu <- (2*6 + 0.5*12 - 1.5*0 - 6)*16.00 /molMass('C6H12O6')
expect_equal(calcCOD('C6H12O6'), CODcellu,5)

# calcCOD results are not influenced by case sensitivity
expect_equal(calcCOD('c6h12o6'), calcCOD('C6H12O6'))

# calcCOD result is null for non organic formula - two letter elements
expect_equal(calcCOD('NaCl'), 0)

# calcCOD gives correct vectorized results
expect_equal(c(calcCOD('CH3CH2OH'), calcCOD('CH2(CH2)2OH')), calcCOD(c('CH3CH2OH', 'CH2(CH2)2OH')))

# stdVol.R --- depends on watVap  
# NTS : could add tests with conversion of units
# standard volume calculation is stable
# convert 100ml at 35 C, rh = 1, 1 atm to 0 C, rh = 0, 1 atm
rh <- 1
# Note new pres.pa argument for enhancement factor
pH2O <- rh * biogas:::watVap(273.15 + 35, pres.pa = 101325) 
dv <- 100 * (101325 - pH2O) / 101325
stdv <- dv*273.15 /  (35+273.15)
expect_equal(stdVol(100, temp = 35, pres = 1, unit.temp = 'C', unit.pres = 'atm'), stdv)

# vol2mass.R --- depends on stdVol, watVap, molMass
# vol2mass results are stables
volBg <- stdVol(100, temp = 273.15 + 20, pres = 101325, rh = 1, temp.std = 273.15, pres.std = 101325, unit.temp = 'K', unit.pres = 'Pa', std.message = FALSE)
mmb <- 0.65*molMass('CH4') + (1 - 0.65)*molMass('CO2')
mvb <- 0.65*vmch4 + (1 - 0.65)*vmco2
db <- mmb/mvb
pH2O <- 1*biogas:::watVap(temp.k = 273.15 + 35) 
mH2O <- molMass('H2O')*pH2O/(((1.5 *101325) - pH2O)*mvb)
mass <- volBg*(db + mH2O)

expect_equal(vol2mass(100, xCH4 = 0.65, temp.hs = 35, temp.vol = 20, pres.hs = 1.5, pres.vol = 1), mass)

# mass2vol.R --- depends on molMass, watVap 
# mass2vol non vectorised result is correct
# Volume of methane if measured mass loss was 3.1 g at 35 C, 1atm, 100% humidity and 65% of methane
mmb <- 0.65*molMass('CH4') + (1 - 0.65)*molMass('CO2')
mvBg <- 0.65*vmch4 + (1 - 0.65)*vmco2
db <- mmb/mvBg
pH2O <- 1*biogas:::watVap(temp.k = (273.15 + 35))
mH2O <- molMass('H2O')*pH2O/((101325 - pH2O)*mvBg)
# Biogas volume
VBg <- 3.1/(db + mH2O)
stdVCH4 <- VBg*0.65*vmch4/mvBg

expect_equal(signif(mass2vol(3.1, xCH4 = 0.65, temp = 35, pres = 1, unit.temp = 'C', unit.pres = 'atm'), 2), signif(stdVCH4, 2))

# planBMP works
expect_equal(
  planBMP(vs.inoc = 10, vs.sub = 100, isr = 2, m.tot = 210, nice = FALSE, warn = FALSE),
  c(vs.inoc = 10, vs.sub = 100, vs.mix = 14.3, isr = 2, m.inoc = 200, m.sub = 10, m.tot = 210, m.vs.sub = 1, m.vs.inoc = 2, m.vs.tot = 3)
)