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Changelog

Source: NEWS.md

ggtargets 0.0.0.9001

Collapse graph

  • dag_collapse(dag, by) collapses a DAG by any node column: the nodes that share a value are merged into one, labeled with its member count, and the edges between groups are drawn once per pair, with an n that counts them. A pipeline of fifty targets in four stages becomes four nodes. by can be a column of your own (via as_dag(nodes =)) or one of the columns tar_dag() returns: description, the one free-form per-target field targets has, type or status. A grouping that makes a cycle is an error naming the groups and the edges behind it. tar_ggplot(collapse_by =) does it in one call. A pipeline’s stages go in the description of its targets, for a block of them with tar_option_set(description = ): see “Collapsing a pipeline by stage” in ?tar_ggplot, the get-started vignette and the “Collapsing a pipeline” article. A stage whose targets have different statuses has no status, and is drawn gray.
  • node_size and edge_width (in ggplot_dag(), dag_layers() and tar_ggplot()) draw a numeric node or edge column as the node’s radius and the edge’s width, for any DAG: for a collapsed graph, node_size = "n" and edge_width = "n" show how many targets and dependencies each node and edge stands for. The ranges are style_metro(node_size_range, edge_width_range), kept within the grid’s spacing. Edges that share a line in the metro layout are drawn whole, the widest first, so the shared line is as wide as the widest edge on it, and each bridge is as wide as the widest edge it lies under. dag_layout() now also returns the dag’s edges, with their extra columns.

Fixes

  • A node with no value in the node_color column (NA) is drawn gray, with no legend entry and no warning from a named palette. The edges drawn in its color (edge_color = "source" or "target") used to be dropped: they had no color, and ggplot2 removed them without a word when it drew the plot, so node_color = "branches" lost the edges out of every stem. NA no longer takes a color from the palette either: with a palette function or an unnamed vector, the other values of a column that has NA move up a color, and a palette one color short of the values plus NA no longer errors.
  • A node column can’t be named row, col, x, y or color_index, the names of the layout’s own columns, which it would silently overwrite (a column x replaced the nodes’ coordinates): as_dag() and dag_layout() stop with an error naming the column.
  • dag_collapse() keeps the by column’s own value when by is seconds, bytes or branches (it summed it, like the others), and leaves a node whose by value is an empty string on its own, like one with an NA.
  • as_dag() stops on an empty node name (it failed with “attempt to use zero-length variable name”), and keeps a factor label column as text (it turned it into integer codes). A node column value of "" gets its palette color or shape like any other value.
  • node_color = NA_character_ and edge_color = NA_character_ are an error, as they would give every node or edge a missing color. dag_layout() stops with a clear message when it is not given a dag.
  • Summaries print “1 node”, “1 edge” and “1 column” in the singular.

ggtargets 0.0.0.9000

Initial release.

Plotting

  • metro_palette() never repeats a color: the 18 distinct dagviz colors (dagviz’s 21-color cycle repeats three of them) are followed by generated, perceptibly distinct colors. A too-short vector palette is an error, not recycled.

  • tar_ggplot() plots the current targets pipeline in one call, in dagviz’s “metro” style: one row per target, thick colored edges with rounded bends, and a white “bridge” wherever two edges cross. It mirrors targets::tar_visnetwork()’s filtering arguments (names/allow/exclude as tidyselect, targets_only, script, store, …).

  • as_dag() builds the same kind of plot from any directed acyclic graph: an edge-list data frame, or a targets::tar_network()-shaped list. tar_dag() is a thin wrapper reading the current pipeline this way.

  • node_color/palette color nodes by a node column, a single color, or dagviz’s own default palette (metro_palette()); targets_status_colors() gives targets’s own status palette for node_color = "status". edge_color colors edges by their source node (the default), their target node, or a single color.

  • Nodes are drawn by their type, as targets::tar_visnetwork() does (targets_node_shapes()): a circle for a regular target, a square for a dynamic-branching one, and an up and a down triangle for an imported function and object (with tar_ggplot(targets_only = FALSE)). A legend names the shapes whenever more than one is drawn, merged with the color legend if node_color is the same column. node_shape picks the column (or one shape for every node) and shapes maps its values to shapes ("circle", "square", "diamond", "triangle", "triangle_down"), so any DAG’s nodes can be shaped by a column too. Nodes are drawn as points, so with fixed_size = FALSE they keep their size, like lines and text, while the spacing stretches; legend keys are circles.

  • A legend taller than the graph (a few nodes with a status and a shape legend) is not cut off: dag_size() and ggsave_dag() make the plot as tall as the legend.

  • Plots have a fixed physical size (one data unit is zoom px at 96 dpi), so nodes, lines and text look the same in every pipeline. dag_size() returns that size and ggsave_dag() saves at it, at dagviz’s own scale (and, with style_metro(minimal_width = 500), its canvas width).

Styling and ggplot2

  • style_metro() exposes every visual detail of the metro style: node/arc size, edge width, label font, bridge color, and more - accepting either dagviz’s own StyleConfig values or their R equivalents.
  • Plots end just past their longest label, rather than leaving a wide blank area on the right: the label text is measured to size the plot. style_metro(minimal_width = 500) gives dagviz’s wider canvas.
  • ggplot_dag(lay, ...) and manual assembly (ggplot() + dag_layers(dag_layout(dag)) + dag_theme()) both return plain ggplot objects that compose with the rest of ggplot2 - titles, themes, patchwork, and so on.

Fidelity

  • The metro layout - node order, column/lane assignment, and pixel geometry - matches dagviz 0.6.0’s own SVG output exactly on all 67 reference fixtures (drawn from real Snakemake rulegraphs via snakevision, hand-built edge cases, and random graphs), including draw order within dagviz’s own SVG groups. The one deliberate difference is the width of the plot, which is fitted to the labels by default (see above); with minimal_width = 500 the view box matches too.