Thurber {NISTnls}R Documentation

Electron mobility data

Description

The Thurber data frame has 37 rows and 2 columns.

Arguments

y A numeric vector of electron mobility values.
x A numeric vector of logs of electron density values.

Format

This data frame contains the following columns:

Details

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.

Source

Thurber, R., NIST (197?). Semiconductor electron mobility modeling.

Examples

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,
           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,
           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,
           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,
           start = c(b5 = 1, b6 = 0.4, b7 = 0.05), alg = "plinear")
fm4


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