Add dedicated plot.parttree method

.Rbuildignore

@@ -6,3 +6,4 @@
 ^_pkgdown\.yml$
 ^docs$
 ^pkgdown$
+^SCRATCH$

.github/workflows/R-CMD-check.yaml

@@ -18,11 +18,11 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: macos-latest,   r: 'release'}
-          - {os: windows-latest, r: 'release'}
+          # - {os: macos-latest,   r: 'release'}
+          # - {os: windows-latest, r: 'release'}
           - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-latest,   r: 'release'}
-          - {os: ubuntu-latest,   r: 'oldrel-1'}
+          # - {os: ubuntu-latest,   r: 'oldrel-1'}
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -3,3 +3,4 @@
 .RData
 docs
 inst/doc
+SCRATCH/

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: parttree
 Title: Visualise simple decision tree partitions
-Version: 0.0.1.9004
+Version: 0.0.1.9005
 Authors@R: c(
     person(given = "Grant",
            family = "McDermott",
@@ -12,8 +12,7 @@ Authors@R: c(
            role = "ctb",
            email = "Achim.Zeileis@R-project.org",
            comment = c(ORCID = "0000-0003-0918-3766")),
-    person(given = "Brian",
-           middle = "Heseung",
+    person(given = "Brian Heseung",
            family = "Kim",
            role = "ctb",
            email = "brhkim@gmail.com",
@@ -27,28 +26,34 @@ Description: Simple functions for plotting 2D decision tree partition plots.
 License: MIT + file LICENSE
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.2
 LazyData: true
 URL: https://github.com/grantmcdermott/parttree,
     http://grantmcdermott.com/parttree
 BugReports: https://github.com/grantmcdermott/parttree/issues
-Depends:
-    ggplot2 (>= 3.4.0)
-Imports: 
-    rpart,
+Imports:
+    graphics,
+    stats,
     data.table,
     partykit,
-    rlang
+    rlang,
+    rpart,
+    ggplot2 (>= 3.4.0),
+    tinyplot (> 0.1.0)
 Suggests: 
     tinytest,
+    tinysnapshot (>= 0.0.3),
+    fontquiver,
+    rsvg,
+    svglite,
     palmerpenguins,
     titanic,
     mlr3,
     parsnip,
     workflows,
     magick,
     imager,
-    patchwork,
     knitr,
     rmarkdown
+Remotes: grantmcdermott/tinyplot
 VignetteBuilder: knitr

NAMESPACE

@@ -6,9 +6,12 @@ S3method(parttree,LearnerRegrRpart)
 S3method(parttree,constparty)
 S3method(parttree,rpart)
 S3method(parttree,workflow)
+S3method(plot,parttree)
 export(geom_parttree)
 export(parttree)
-import(ggplot2)
 importFrom(data.table,":=")
 importFrom(data.table,.SD)
 importFrom(data.table,fifelse)
+importFrom(graphics,par)
+importFrom(stats,reformulate)
+importFrom(tinyplot,tinyplot)

NEWS.md

@@ -1,19 +1,34 @@
-# parttree 0.0.1.9004
+# parttree 0.0.1.9005
 
-To be released as 0.1
+To be released as 0.1.0
+
+#### Breaking changes
+
+* Move ggplot2 to Suggests, following the addition of native (base R)
+`plot.parttree` method. The `geom_parttree()` function now checks whether
+ggplot2 is available on the user's system before executing any code. (#18)
+* The `flipaxes` argument has been renamed to `flip`, e.g.
+`parttree(..., flip = TRUE)`. (#18)
 
 #### Improvements
 
-* Major speed-up for extracting parttree nodes and coordinates on complicated trees (#15).
-* Add method for tidymodels workflows objects fitted with `"rpart"` engine (#7 by @juliasilge).
+* Parttree objects now have their own class with a dedicated `plot.parttree`
+method, powered by tinyplot. (#18)  
+* Major speed-up for extracting parttree nodes and coordinates on complicated
+trees. (#15)
+* Add method for tidymodels workflows objects fitted with `"rpart"` engine. (#7
+by @juliasilge).
 
 #### Bug fixes
 
-* Support for negative values (#6 by @pjgeens).
-* Better handling of single-level factors and `flipaxes` (#5).
+* Support for negative values. (#6 by @pjgeens)
+* Better handling of single-level factors and `flip(axes)`. (#5)
 
 #### Internals
 
+* Several dependency adjustments, e.g. tinyplot to Imports and ggplot2 to
+Suggests. (#18)
+* Added SVG snapshots for image-based tests. (#18)
 * Bump ggplot2 version dependency to match deprecated functions from 3.4.0.
 * Switched to "main" as primary GitHub branch for development.
 * Added two dedicated vignettes.

R/geom_parttree.R

@@ -1,18 +1,18 @@
-#' @title Visualise tree partitions
+#' @title Visualise tree partitions with ggplot2
 #'
 #' @description `geom_parttree()` is a simple extension of
 #'   [ggplot2::geom_rect()]that first calls
 #'   [parttree()] to convert the inputted tree object into an
-#'   amenable data frame.
+#'   amenable data frame. Please note that `ggplot2` is not a hard dependency
+#'   of `parttree` and should thus be installed separately on the user's system.
 #' @param data An [rpart::rpart.object] or an object of compatible
 #'   type (e.g. a decision tree constructed via the `partykit`, `tidymodels`, or
 #'   `mlr3` front-ends).
-#' @param flipaxes Logical. By default, the "x" and "y" axes variables for
+#' @param flip Logical. By default, the "x" and "y" axes variables for
 #'   plotting are determined by the first split in the tree. This can cause
 #'   plot orientation mismatches depending on how users specify the other layers
 #'   of their plot. Setting to `TRUE` will flip the "x" and "y" variables for
 #'   the `geom_parttree` layer.
-#' @import ggplot2
 #' @inheritParams ggplot2::layer
 #' @inheritParams ggplot2::geom_point
 #' @inheritParams ggplot2::geom_segment
@@ -39,7 +39,9 @@
 #' @seealso [parttree()], [ggplot2::geom_rect()].
 #' @export
 #' @examples
-#' library(rpart)
+#' library(parttree) # this package
+#' library(rpart)    # decision trees
+#' library(ggplot2)  # ggplot2 must be loaded separately
 #'
 #' ### Simple decision tree (max of two predictor variables)
 #'
@@ -67,8 +69,7 @@
 #' ## Oops
 #' p2 + geom_parttree(data = iris_tree, aes(fill=Species), alpha = 0.1)
 #'
-#' ## Fix with 'flipaxes = TRUE'
-#' p2 + geom_parttree(data = iris_tree, aes(fill=Species), alpha = 0.1, flipaxes = TRUE)
+#' ## Fix with 'flip = TRUE'
 #'
 #'
 #' ### Various front-end frameworks are also supported, e.g.:
@@ -106,19 +107,28 @@ geom_parttree =
   function(mapping = NULL, data = NULL,
            stat = "identity", position = "identity",
            linejoin = "mitre", na.rm = FALSE, show.legend = NA,
-           inherit.aes = TRUE, flipaxes = FALSE, ...) {
-    pdata = parttree(data, flipaxes = flipaxes)
+           inherit.aes = TRUE, flip = FALSE, ...) {
+
+    ggplot2_installed = requireNamespace("ggplot2", quietly = TRUE)
+    if (isFALSE(ggplot2_installed)) {
+      stop("Please install the ggplot2 package.", .call = FALSE)
+    } else if (utils::packageVersion("ggplot2") < "3.4.0") {
+      stop("Please install a newer version of ggplot2 (>= 3.4.0).")
+    }
+
+
+    pdata = parttree(data, flip = flip)
     mapping_null = is.null(mapping)
     mapping$xmin = quote(xmin)
     mapping$xmax = quote(xmax)
     mapping$ymin = quote(ymin)
     mapping$ymax = quote(ymax)
     if (mapping_null) {
-      mapping = aes_all(mapping)
+      mapping = ggplot2::aes_all(mapping)
     }
     mapping$x = rlang::quo(NULL)
     mapping$y = rlang::quo(NULL)
-    layer(
+    ggplot2::layer(
       stat = stat, geom = GeomParttree,
       data = pdata,
       mapping = mapping,
@@ -129,11 +139,13 @@ geom_parttree =
 
 ## Underlying ggproto object
 GeomParttree =
-  ggproto(
-    "GeomParttree", GeomRect,
-    default_aes = aes(colour = "black", linewidth = 0.5, linetype = 1,
+  ggplot2::ggproto(
+    "GeomParttree", ggplot2::GeomRect,
+    default_aes = ggplot2::aes(colour = "black", linewidth = 0.5, linetype = 1,
                       x=NULL, y = NULL,
                       fill = NA, alpha = NA
     ),
     non_missing_aes = c("x", "y", "xmin", "xmax", "ymin", "ymax")
   )
+
+