Hahn1 {NISTnls} | R Documentation |
The Hahn1
data frame has 236 rows and 2 columns of data from a
study on the thermal expansion of copper.
y |
A numeric vector of values of the coefficient of thermal expansion. |
x |
A numeric vector of temperatures (K). |
This data frame contains the following columns:
These data are the result of a NIST study involving the thermal expansion of copper. The response variable is the coefficient of thermal expansion, and the predictor variable is temperature in degrees Kelvin.
Hahn, T., NIST (197?). Copper Thermal Expansion Study.
library(NISTnls) data(Hahn1) plot(y ~ x, data = Hahn1) fm1 <- nls(y ~ (b1+b2*x+b3*x**2+b4*x**3) / (1+b5*x+b6*x**2+b7*x**3), data = Hahn1, trace = TRUE, start = c(b1 = 10, b2 = -1, b3 = 0.05, b4 = -0.00001, b5 = -0.05, b6 = 0.001, b7 = -0.000001)) fm2 <- nls(y ~ (b1+b2*x+b3*x**2+b4*x**3) / (1+b5*x+b6*x**2+b7*x**3), data = Hahn1, trace = TRUE, start = c(b1 = 1, b2 = -0.1, b3 = 0.005, b4 = -0.000001, b5 = -0.005, b6 = 0.0001, b7 = -0.0000001)) fm3 <- nls(y ~ cbind(1, x, x^2, x^3)/(1+x*(b5+x*(b6+x*b7))), data = Hahn1, trace = TRUE, algorithm = "plinear", start = c(b5 = -0.05, b6 = 0.001, b7 = -0.000001)) fm4 <- nls(y ~ cbind(1, x, x^2, x^3)/(1+x*(b5+x*(b6+x*b7))), data = Hahn1, trace = TRUE, algorithm = "plinear", start = c(b5 = -0.005, b6 = 0.0001, b7 = -0.0000001))