saturationpressure.r

In DustinMoriarty/PsychrometricChart: Moist Air State R

SaturationPressure <- function(T){

	C1 = -5.6745359e3
	C2 = 6.3925247
	C3 = -9.6778430e-3
	C4 = 6.2215701e-7
	C5 = 2.0747825e-9
	C6 = -9.484024e-13
	C7 = 4.1635019
	C8 = -5.8002206e3
	C9 = 1.3914993
	C10 = -4.8640239e-2
	C11 = 4.1764768e-5
	C12 = -1.4452093e-8
	C13 = 6.5459673

	p <- 	ifelse(T>=173.15 & T < 273.15,
	    exp(C1/T + C2 + C3*T + C4*T^2 + C5*T^3 + C6*T^4 + C7 * log(T)),
	ifelse(T>= 273.15 & T< 473.15,
	    exp(C8/T+C9+C10*T+C11*T^2+C12*T^3+C13*log(T)),
	NA))


return(p)
}