small additions

.github/CONTRIBUTING.md

@@ -0,0 +1,17 @@
+# Contributing to IWMM
+
+If you have any ideas for improving this project, or want to contribute something,
+feel free to open an issue or pull request.
+
+## Pull request process
+
+*  New code should follow the tidyverse [style guide](http://style.tidyverse.org).
+You can use the [styler](https://CRAN.R-project.org/package=styler) package to
+apply these styles, but please don't restyle code that has nothing to do with 
+your PR.
+* You can use lintr::lint_package() to check for any styling issues
+* You can run styler::style_pkg() to automatically fix styling issues
+*  We use [roxygen2](https://cran.r-project.org/package=roxygen2), with
+[Markdown syntax](https://cran.r-project.org/web/packages/roxygen2/vignettes/rd-formatting.html), 
+for documentation.  
+*  We use [testthat](https://cran.r-project.org/package=testthat) for testing.

R/example_iwmm_model.R

@@ -39,7 +39,10 @@ iwmm_examples <- function() {
 }",
         data = list(
           N = as.integer(10),
-          x = c(1.4395244, 1.7698225, 3.5587083, 2.0705084, 2.1292877, 2.4609162, 0.7349388, 1.3131471, 1.5543380, 23.7150650)
+          x = c(
+            1.4395244, 1.7698225, 3.5587083, 2.0705084, 2.1292877,
+            2.4609162, 0.7349388, 1.3131471, 1.5543380, 23.7150650
+          )
         )
       )
   )

R/moment_match.R

@@ -150,7 +150,7 @@ moment_match.matrix <- function(x,
   }
 
   if (is.null(expectation_fun)) {
-    list("draws" = draws, "log_weights" = lw, "pareto_k" = k)
+    adapted_draws <- list("draws" = draws, "log_weights" = lw, "pareto_k" = k)
   } else {
     lwf <- compute_lwf(draws, lw, expectation_fun, log_expectation_fun, ...)
     psisf <- suppressWarnings(loo::psis(lwf))
@@ -360,12 +360,15 @@ moment_match.matrix <- function(x,
       expectation <- colSums(w * expectation_fun(draws, ...))
     }
 
-    list(
+    adapted_draws <- list(
       "expectation" = expectation,
       "pareto_k" = k,
       "pareto_kf" = kf,
       "draws" = draws,
       "log_weights" = lw
     )
   }
+  class(adapted_draws) <- c("adapted_draws", class(adapted_draws))
+
+  return(adapted_draws)
 }