tests/ethane_data.R

In chapensk: Estimation of Gas Properties from the Lennard-Jones Potential

library(chapensk)

# graphics parameters
width <- 10
height <- 5
mar <- c(5.1, 4.6, 0.2, 0.6)
mai <- c(1.02, 0.82, 0.04, 0.04)
family <- "Helvetica"
pointsize <- 12
lwd <- 1

c2h6 <- Gas("ethane")

if (interactive()) {
  if (exists("outputDevice")) {
    if (outputDevice == "pdf") pdf(file = "man/figures/ethane.pdf", width = width, height = height, family = family, pointsize = pointsize)
    if (outputDevice == "svg") svg(file = "man/figures/ethane.svg", width = width, height = height, family = family, pointsize = pointsize)
  }
  split.screen(figs = c(1, 2))
}

ethane_viscosity <- subset(ethane_data, (property == "viscosity") & (T >= 90) & (T <= 675), select = c(T, value))
sigma0 <- c2h6$sigma
epsk0 <- c2h6$epsk
c2h6$zeta <- 0
print("Literature data")
print(c2h6$sigma)
print(c2h6$epsk)
ethane_viscosity$value <- 1E-6 * ethane_viscosity$value
ethane_B <- subset(ethane_data, (property == "BQFH") & (T >= 220) & (T <= 623))
ethane_B$value <- 1E-6 * ethane_B$value
fit <- c2h6$fit_B_viscosity_data(ethane_B, ethane_viscosity, log = FALSE)
sigma1 <- c2h6$sigma
epsk1 <- c2h6$epsk
zeta1 <- c2h6$zeta
print("Fit of B and viscosity data")
print(c2h6$sigma)
print(c2h6$epsk)
print(c2h6$zeta)
stopifnot(round(c2h6$sigma, 2) == 4.36)
stopifnot(round(c2h6$epsk, 1) == 244.8)
c2h6$sigma <- sigma0
c2h6$epsk <- epsk0
c2h6$zeta <- 0
if (interactive()) {
  screen(1)
}
par(mai = mai, mar = mar)
c2h6$fit_viscosity_data(ethane_viscosity)
lines(ethane_viscosity$T, 1E6 * c2h6$viscosity(ethane_viscosity$T, sigma = sigma1, epsk = epsk1, zeta = zeta1), col = "red", lty = 2)
if (interactive()) {
  legend("top", bty = "n", legend = "(a)")
  screen(2)
}
print("Fit of viscosity data")
print(c2h6$sigma)
print(c2h6$epsk)
stopifnot(round(c2h6$sigma, 2) == 4.38)
stopifnot(round(c2h6$epsk, 1) == 235.7)
par(mai = mai, mar = mar)
c2h6$zeta <- 0
c2h6$fit_B_data(ethane_B)
lines(ethane_B$T, 1E6 * c2h6$B(ethane_B$T, sigma = sigma1, epsk = epsk1), col = "red", lty = 2)
if (interactive()) {
  legend("top", bty = "n", legend = "(b)")
  close.screen()
  dev.off()
}
print("Fit of B data")
print(c2h6$sigma)
print(c2h6$epsk)
stopifnot(round(c2h6$sigma, 2) == 4.95)
stopifnot(round(c2h6$epsk, 1) == 202.0)