| Thurber(NISTnls) | R Documentation |
The Thurber data frame has 37 rows and 2 columns.
y |
A numeric vector of electron mobility values. |
x |
A numeric vector of logs of electron density values. |
This data frame contains the following columns:
These data are the result of a NIST study involving semiconductor electron mobility. The response variable is a measure of electron mobility, and the predictor variable is the natural log of the density.
Thurber, R., NIST (197?). Semiconductor electron mobility modeling.
library(NISTnls)
data(Thurber)
plot(y ~ x, data = Thurber)
fm1 <- nls(y ~ (b1+x*(b2+x*(b3+b4*x))) / (1+x*(b5+x*(b6+x*b7))),
data = Thurber, trace = TRUE, warnOnly = TRUE,
start = c(b1 = 1000, b2 = 1000, b3 = 400, b4 = 40,
b5 = 0.7, b6 = 0.3, b7 = 0.03))
fm2 <- nls(y ~ (b1+x*(b2+x*(b3+b4*x))) / (1+x*(b5+x*(b6+x*b7))),
data = Thurber, trace = TRUE, warnOnly = TRUE,
start = c(b1 = 1300, b2 = 1500, b3 = 500, b4 = 75,
b5 = 1, b6 = 0.4, b7 = 0.05))
fm3 <- nls(y ~ outer(x, 0:3, "^")/(1+x*(b5+x*(b6+x*b7))),
data = Thurber, trace = TRUE, warnOnly = TRUE,
start = c(b5 = 0.7, b6 = 0.3, b7 = 0.03), alg = "plinear")
fm4 <- nls(y ~ outer(x, 0:3, "^")/(1+x*(b5+x*(b6+x*b7))),
data = Thurber, trace = TRUE, warnOnly = TRUE,
start = c(b5 = 1, b6 = 0.4, b7 = 0.05), alg = "plinear")
fm4