Hi,

I need to calculate the volume of a tree by integrating the “taper” function below. I did this code in R, and it works well, but now that I am trying to code it in GAMS I cannot find a way of doing that.

How do we calculate integrals in GAMS?

Any suggestions?

midh ← 13.5

midd ← 15.1

taper1 ← function(midh){

taper2 ← function(midd){

tFactorSBD ← 1.3/midh

qFactorSBD ← (0/100)/midh

YFactorSBD ← (1-qFactorSBD^0.5)/(1-tFactorSBD^0.5)

aux1SBD ← 0.6624965*(YFactorSBD^0.1)+ 0.3781478*(qFactorSBD^4)

aux2SBD ← -0.4418430*asin(1-sqrt(qFactorSBD))
aux3SBD ← -0.5154988/exp(midd/midh)
aux4SBD ← 0.0197963*midd^YFactorSBD

ExpFactorSBD ← aux1SBD+ aux2SBD+ aux3SBD+ aux4SBD

diam ← 0.8795844*(midd^0.9457765)

*(midh^0.1061692)*(YFactorSBD^ExpFactorSBD)

area<- pi*((diam/2)^2)/10000

}

}

## volume<- function(midh){

integrate(taper1(midh), lower = 0,upper = midh)$value

}

Thanks

Ana