`semEff`

provides functionality to automatically calculate
direct, indirect, and total effects for ‘piecewise’ structural equation
models, comprising lists of fitted models representing structured
equations (Lefcheck, 2016; Shipley, 2000, 2009). Confidence intervals
are provided via bootstrapping.

Currently supported model classes are `"lm"`

,
`"glm"`

, `"lmerMod"`

, `"glmerMod"`

,
`"lmerModLmerTest"`

, `"gls"`

, and
`"betareg"`

.

You can install the released version of `semEff`

from CRAN with:

`install.packages("semEff")`

And the development version from GitHub with:

`::install_github("murphymv/semEff@dev") devtools`

The primary function is `semEff()`

,
which returns an object of class `"semEff"`

with associated
`print()`

and `summary()`

methods. Everything can
technically be accomplished in a single call to `semEff()`

;
however, since bootstrapping is employed to generate resamples for
confidence intervals (via `bootEff()`

),
it is usually preferable to save these estimates separately prior to
calling `semEff()`

– allowing more flexibility and saving
time if/when recalling the function.

Package functions are well-documented and most include some short examples. In addition, see the following vignettes for some longer demonstrations:

Analysing direct vs. indirect effects of landscape location on plant species richness

Predicting and plotting indirect effects of degree days to bud burst on tree growth

Lefcheck, J. S. (2016). piecewiseSEM: Piecewise structural equation
modelling in R for ecology, evolution, and systematics. *Methods in
Ecology and Evolution*, *7*(5), 573–579. doi:10/f8s8rb

Shipley, B. (2000). A New Inferential Test for Path Models Based on
Directed Acyclic Graphs. *Structural Equation Modeling: A
Multidisciplinary Journal*, *7*(2), 206–218. doi:10/cqm32d

Shipley, B. (2009). Confirmatory path analysis in a generalized
multilevel context. *Ecology*, *90*(2), 363–368. doi:10/bqd43d