Versions after brokenstick 0.62.1
(May 2020) have a substantially changed interface. In particular, later versions (starting with brokenstick 0.70.0
) include the following changes:
brokenstick
adopts the tidymodels
philosophy. It is now possible to fit a model using four different interfaces. There is no need anymore the hardcode variable names in the source data.
Version 0.70.0
introduces a new estimation method, the Kasim-Raudenbush sampler. The new method is more flexible and faster than lme4::lmer()
when the number of knots is large.
Version 0.70.0
introduces two simple correlation models that may be used to smooth out the variance-covariance matrix of the random effects.
The definition of the brokenstick
class has changed. Objects of class brokenstick
do no longer store the training data.
The brokenstick_export
class is retired.
The predict()
function is fully rewritten as has now a new interface. Since the brokenstick
class does not store the training data anymore, the predict()
function now obtains a new_data
argument. Syntax that worked for brokenstick
package before 0.70.0
does not work anymore and should be updated. The shape
argument replaces the output
argument.
The plot()
function is rewritten, and now requires a new_data
specification.
Replaced functions: brokenstick()
replaces fit_brokenstick()
, predict.brokenstick()
replaces predict.brokenstick_export()
, get_r2()
replaces get_pev()
Removed functions: get_data()
, get_X()
, export()
We recommend changing your code to reflect the above changes. If needed, the old version 0.62.1
can be installed as
library(devtools)
install_github("growthcharts/brokenstick@V0.62.1")
Fit model, old version:
data <- brokenstick::smocc_200
fit <- brokenstick(y = data$hgt.z, x = data$age, subjid = data$subjid)
Fit model, version 0.75.0
and higher:
data <- brokenstick::smocc_200
# formula interface
fit1 <- brokenstick(hgt.z ~ age | id, data)
# XY interface - numeric vector
fit2 <- with(data, brokenstick(age, hgt.z, id))
# XY interface - data.frame
fit3 <- with(data, brokenstick(data.frame(age), hgt.z, id))
# XY interface - matrix
tt <- as.matrix(data[, c(1, 2, 7)])
fit4 <- brokenstick(tt[, "age", drop = FALSE],
tt[, "hgt.z", drop = FALSE],
tt[, "id", drop = FALSE])
All fitted models are identical.
Predict model, old version:
# predict at observed data
p1 <- predict(fit)
# predict at knots
p2 <- predict(fit, at = "knots")
# predict at both observed data and knots
p3 <- predict(fit, at = "both")
# predict knots, broad version
p4 <- predict(fit, at = "knots", output = "broad")
Predict model, new version:
Proportion explained variance, old version
get_pev(fit)
get_r2(fit1, data)
#> [1] 0.8121548
lmer
and kr
methodsbrokenstick()
for model fittingpredict()
for trajectory plotting