bending_fit_3: Euler-Bernoulli bending with 3 parameters
In kmiddleton/EulerBending: Euler-Bernoulli Bending

Description Usage Arguments Value Author(s) Examples

View source: R/bending_fit_3.R

Euler-Bernoulli bending with 3 parameters. EI is allowed to vary linearly along the length of the beam.

1	bending_fit_3(parms, optim = TRUE, n = 1000, beam_length, data)

`parms`	vector. 3 parameters for fitting (C1, C2, Offset). C1 is the intercept, C2 is the slope, and the Offset allows the zero point to not be at `(0,0)`.
`optim`	bernoulli. If `TRUE`, only the sum of squares is returned
`n`	integer. Number of divisions for the theoretical beam. Defaults to 1000.
`beam_length`	integer. Beam length in m.
`data`	data.frame. Observed data.

If optim = FALSE, a list containing the theoretical bone (test_mat), the observed data (dat), and the sum of squares (value).

Kevin Middleton

# Pixels per cm
scale_pix <- 107

# Length in m
beam_length <- 0.03

glosso$Trial <- as.factor(glosso$Trial)

glosso$x <- glosso$x_pix/scale_pix/100
glosso$u <- glosso$u_pix/scale_pix/100

fit_3_optim <- nmkb(c(0.001, 0, 0), bending_fit_3,
                    lower = rep(-1, 3),
                    upper = rep(1, 3),
                    beam_length = beam_length,
                    data = glosso)
fit_3_optim$value

fit_3 <- bending_fit_3(parms = c(fit_3_optim$par[1],
                                 fit_3_optim$par[2],
                                 fit_3_optim$par[3]),
                                 optim = FALSE,
                                 beam_length = beam_length,
                                 data = glosso)
fit_3$value

test_mat <- fit_3$test_mat
dat2 <- fit_3$dat

p1 <- ggplot(dat2, aes(x = x, y = u_P)) +
  geom_point(aes(color = Trial), size = 3) +
  geom_line(data = test_mat, aes(x = x, y = u_P),
            color = I("red")) +
  geom_point(data = data.frame(x = 0, y = 0), aes(x, y))
p2 <- ggplot(test_mat, aes(x = x, y = EI)) + geom_line()
grid.arrange(p1, p2, nrow = 2)
c(min(test_mat$EI), max(test_mat$EI))