| Type: | Package | 
| Title: | Bayesian Grouped Weighted Quantile Sum Regression | 
| Version: | 0.1.1 | 
| Author: | David Wheeler, Matthew Carli | 
| Maintainer: | Matthew Carli <carlimm@mymail.vcu.edu> | 
| Description: | Fits Bayesian grouped weighted quantile sum (BGWQS) regressions for one or more chemical groups with binary outcomes. Wheeler DC et al. (2019) <doi:10.1016/j.sste.2019.100286>. | 
| License: | GPL-3 | 
| Encoding: | UTF-8 | 
| LazyData: | true | 
| RoxygenNote: | 7.1.1 | 
| Depends: | R (≥ 4.0.0) | 
| SystemRequirements: | JAGS | 
| Imports: | coda, stats, rjags, stringr, plyr | 
| Suggests: | testthat | 
| NeedsCompilation: | no | 
| Packaged: | 2022-01-20 22:32:42 UTC; Matt Carli | 
| Repository: | CRAN | 
| Date/Publication: | 2022-01-20 22:42:54 UTC | 
Bayesian Grouped WQS Regression
Description
This function fits a Bayesian grouped weighted quantile sum (BGWQS) regression model.
Usage
bgwqs.fit(
  y,
  x,
  z,
  x.s,
  n.quantiles = 4,
  working.dir,
  n.chains = 1,
  n.iter = 10000,
  n.burnin = 5000,
  n.thin = 1,
  n.adapt = 500,
  DIC = FALSE
)
Arguments
| y | A vector containing outcomes. | 
| x | A matrix of component data. | 
| z | A vector or matrix of controlling covariates. | 
| x.s | A vector of the number of components in each index. | 
| n.quantiles | The number of quantiles to apply to the component data. | 
| working.dir | A file path to the directory. | 
| n.chains | The number of Markov chains; must be a positive integer. | 
| n.iter | The number of total iterations per chain, including burn in. | 
| n.burnin | The number of iterations to discard at the beginning. | 
| n.thin | The thinning rate; must be a positive integer. | 
| n.adapt | The number of adaption iterations. | 
| DIC | Logical; whether or not the user desires the function to return DIC. | 
Value
A list which includes BUGS output, sample chains post-burnin, and convergence test results.
Examples
## Not run: 
data("simdata")
group_list <- list(c("pcb_118", "pcb_138", "pcb_153", "pcb_180", "pcb_192"),
                   c("as", "cu", "pb", "sn"),
                   c("carbaryl", "propoxur", "methoxychlor", "diazinon", "chlorpyrifos"))
x.s <- make.x.s(simdata, 3, group_list)
X <- make.X(simdata, 3, group_list)
Y <- simdata$Y
work_dir <- tempdir()
results <- bgwqs.fit(y = Y, x = X, x.s = x.s, n.quantiles=4,
                     working.dir = work_dir,
                     n.chains = 1, n.iter = 10000, n.burnin = 5000, n.thin = 1, n.adapt = 500)
## End(Not run)
Forms matrix of components
Description
This function returns a matrix of component variables, X. The user can specify the desired chemicals and order by creating a list of string vectors, each vector containing the variable names of all desired elements of that group.
Usage
make.X(df, num.groups, groups)
Arguments
| df | A dataframe containing named component variables | 
| num.groups | An integer representing the number of component groups desired | 
| groups | A list, each item in the list being a string vector of variable names for one component group | 
Value
A matrix of component variables
Examples
data("simdata")
group_list <- list(c("pcb_118", "pcb_138", "pcb_153", "pcb_180", "pcb_192"),
                   c("as", "cu", "pb", "sn"),
                   c("carbaryl", "propoxur", "methoxychlor", "diazinon", "chlorpyrifos"))
X <- make.X(simdata, 3, group_list)
X
Forms component group ID vector of X
Description
This function returns a vector which lets WQS.fit know the size and order of groups in X
Usage
make.x.s(df, num.groups, groups)
Arguments
| df | A dataframe containing named component variables | 
| num.groups | An integer representing the number of component groups desired | 
| groups | A list, each item in the list being a string vector of variable names for one component group | 
Value
A vector of integers, each integer relating how many columns are in each group
Examples
data("simdata")
group_list <- list(c("pcb_118", "pcb_138", "pcb_153", "pcb_180", "pcb_192"),
                   c("as", "cu", "pb", "sn"),
                   c("carbaryl", "propoxur", "methoxychlor", "diazinon", "chlorpyrifos"))
x.s <- make.x.s(simdata, 3, group_list)
x.s
Simulated data of chemical concentrations and one binary outcome variable
Description
Data were simulated to have 0.7 in-group correlation and 0.3 between-group correlation. There are three groups, with the third being significantly correlated to the outcome variable.
Usage
simdata
Format
A data frame with 1000 rows and 15 variables:
- pcb_118
- a numeric vector; part of group 1 
- pcb_138
- a numeric vector; part of group 1 
- pcb_153
- a numeric vector; part of group 1 
- pcb_180
- a numeric vector; part of group 1 
- pcb_192
- a numeric vector; part of group 1 
- as
- a numeric vector; part of group 2 
- cu
- a numeric vector; part of group 2 
- pb
- a numeric vector; part of group 2 
- sn
- a numeric vector; part of group 2 
- carbaryl
- a numeric vector; part of group 3 
- propoxur
- a numeric vector; part of group 3 
- methoxychlor
- a numeric vector; part of group 3 
- diazinon
- a numeric vector; part of group 3 
- chlorpyrifos
- a numeric vector; part of group 3 
- Y
- a numeric vector; the outcome variable 
Generates Plots of weights by group
Description
This function takes the object created by the bgwqs.fit function and a vector of group names and generates a random forest variable importance plot for each group. The weights in each group are listed in descending order.
Usage
weight.plot(fit.object, group.names, group.list, x.s)
Arguments
| fit.object | The object that is returned by the bgwqs.fit function | 
| group.names | A string vector containing the name of each group included in the BGWQS regression. Will be used for plot titles. | 
| group.list | A list, each item in the list being a string vector of variable names for one component group. | 
| x.s | A vector of the number of components in each index. | 
Value
A plot for each group of the BGWQS regression