Add print method for sdmTMB_cv() #319

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: sdmTMB
 Title: Spatial and Spatiotemporal SPDE-Based GLMMs with 'TMB'
-Version: 0.6.0.9009
+Version: 0.6.0.9010
 Authors@R: c(
     person(c("Sean", "C."), "Anderson", , "[email protected]",
            role = c("aut", "cre"),

NAMESPACE

@@ -14,6 +14,7 @@ S3method(nobs,sdmTMB)
 S3method(plot,sdmTMBmesh)
 S3method(predict,sdmTMB)
 S3method(print,sdmTMB)
+S3method(print,sdmTMB_cv)
 S3method(ranef,sdmTMB)
 S3method(residuals,sdmTMB)
 S3method(simulate,sdmTMB)

NEWS.md

@@ -1,5 +1,7 @@
 # sdmTMB (development version)
 
+* Add print method for `sdmTMB_cv()` output. #319
+
 * Add progress bar to `simulate.sdmTMB()`. #346
 
 * Add AUC and TSS examples to cross validation vignette. #268

R/cross-val.R

@@ -453,7 +453,7 @@ sdmTMB_cv <- function(
   pdHess <- vapply(out, `[[`, "pdHess", FUN.VALUE = logical(1L))
   max_grad <- vapply(out, `[[`, "max_gradient", FUN.VALUE = numeric(1L))
   converged <- all(pdHess)
-  list(
+  out <- list(
     data = data,
     models = models,
     fold_loglik = fold_cv_ll,
@@ -462,9 +462,35 @@ sdmTMB_cv <- function(
     pdHess = pdHess,
     max_gradients = max_grad
   )
+  `class<-`(out, "sdmTMB_cv")
 }
 
 log_sum_exp <- function(x) {
   max_x <- max(x)
   max_x + log(sum(exp(x - max_x)))
 }
+
+#' @export
+#' @import methods
+print.sdmTMB_cv <- function(x, ...) {
+  nmods <- length(x$models)
+  nconverged <- sum(x$converged)
+  cat(paste0("Cross validation of sdmTMB models with ", nmods, " folds.\n"))
+  cat("\n")
+  cat("Summary of the first fold model fit:\n")
+  cat("\n")
+  print(x$models[[1]])
+  cat("\n")
+  cat("Access the rest of the models in a list element named `models`.\n")
+  cat("E.g. `object$models[[2]]` for the 2nd fold model fit.\n")
+  cat("\n")
+  cat(paste0(nconverged, " out of ", nmods, " models are consistent with convergence.\n"))
+  cat("Figure out which folds these are in the `converged` list element.\n")
+  cat("\n")
+  cat(paste0("Out-of-sample log likelihood for each fold: ", paste(round(x$fold_loglik, 2), collapse = ", "), ".\n"))
+  cat("Access these values in the `fold_loglik` list element.\n")
+  cat("\n")
+  cat("Sum of out-of-sample log likelihoods:", round(x$sum_loglik, 2), "\n")
+  cat("More positive values imply better out-of-sample prediction.\n")
+  cat("Access this value in the `sum_loglik` list element.\n")
+}

tests/testthat/test-cross-validation.R

@@ -12,6 +12,7 @@ test_that("Basic cross validation works", {
     data = d, mesh = spde,
     family = tweedie(link = "log"), time = "year", k_folds = 2
   )
+  print(x)
   expect_equal(class(x$sum_loglik), "numeric")
   expect_equal(x$sum_loglik, sum(x$data$cv_loglik))
   expect_equal(x$sum_loglik, sum(x$fold_loglik))