Save Diagram to File

Renders the enrollment diagram and saves it to a file. Supported formats are PDF, PNG, SVG, and TIFF (inferred from the file extension). The grid engine renders via R graphics devices; the dot engine pipes Graphviz output through the system dot binary. Dimensions are computed automatically from diagram content via recdims() unless overridden.

Usage

flowsave(
  x,
  file,
  engine = c("grid", "dot"),
  width = NULL,
  height = NULL,
  dpi = 300,
  sans_serif = TRUE,
  ...
)

Arguments

x

A selecta object.

file

Character string. Output file path. The format is inferred from the file extension. Supported extensions: .pdf, .png, .svg, .tif/.tiff (all engines); .dot (dot engine only, writes the raw DOT source).

engine

Character string. One of "grid" (the default, uses R's grid graphics) or "dot" (uses the system Graphviz binary). The dot engine requires dot to be installed and on the system PATH.

width

Numeric or NULL. Width in inches. If NULL (default), computed automatically. For the dot engine, omit to let Graphviz determine dimensions from layout.

height

Numeric or NULL. Height in inches. If NULL (default), computed automatically. For the dot engine, omit to let Graphviz determine dimensions from layout.

dpi

Integer. Resolution in dots per inch for raster formats (PNG, TIFF). Default 300. Honored by both engines. Mirrors the dpi argument of ggplot2::ggsave().

sans_serif

Logical. dot engine only. If TRUE (default), the rendered SVG/PDF text is displayed in a sans-serif fallback chain (Helvetica, Arial, "Liberation Sans", "DejaVu Sans", sans-serif) regardless of the layout font. Layout boxes are still sized using the metrics of the font set via font_family, so the result preserves all margins. Set to FALSE to retain the layout font as the displayed font.

...

Additional styling and formatting arguments forwarded to the selected engine; see flowchart() for the full descriptions.

engine = "grid"

cex, cex_side, cex_phase, box_fill, phase_fill, vpad, margin, font_family, number_format

engine = "dot"

formatting, bullets, count_first, number_format, ortho, font_family, padding_pt, padding_adjust, box_fill, side_fill, border_col, arrow_col, source_fill, source_header_fill, source_header_text, phase_labels, phase_fill, phase_text_col, side_gap_in, rank_sep, node_sep

Value

Invisibly returns the output file path.

Details

flowsave() renders a flow directly to a file, inferring the format from the extension and choosing dimensions automatically unless width and height are given. With engine = "grid" it draws through R's graphics devices, producing either vector formats (.pdf, .svg) or raster formats (.png, .tiff).

For raster formats, flowsave() prefers the ragg device when installed, with fallback to the base png()/tiff() devices otherwise. Using these devices is generally advised for raster output over other devices such as cairo since some cairo configurations drop the plotmath italics in the count labels. The dpi argument mirrors ggplot2::ggsave() for raster resolution.

With engine = "dot", flowsave() renders a graphic based on a Graphviz DOT string: a .dot extension writes the source text directly and needs no external software, whereas image output shells out to the system dot binary and therefore requires Graphviz on the PATH.

When sizing automatically, flowsave() calls recdims() once and reuses the computed layout, so a separate recdims() call is unnecessary. With the grid engine, leaving either dimension at its default also reports the content-derived recommendation through a message(); supply both width and height to size manually and silence it. The dot engine instead lets Graphviz size the output from the layout, so no recommendation is reported.

See also

flowchart for interactive rendering, recdims for dimension recommendations

Other flowchart output functions: flowchart(), print.selecta(), recdims(), summary.selecta()

Examples

flow <- enroll(n = 500) |>
  exclude("Ineligible", n = 50) |>
  endpoint("Analysis")

# \donttest{
# Grid engine (default). Files are written under tempdir() here so
# the example respects CRAN's no-write policy; in practice any
# desired path may be supplied.
flowsave(flow, file.path(tempdir(), "consort.pdf"))
#> Recommended plot dimensions: width = 3.4 in, height = 2.5 in
flowsave(flow, file.path(tempdir(), "consort.png"),
         width = 8, height = 10)
# }

# \donttest{
# DOT engine writing a .dot source file requires no external software.
flowsave(flow, file.path(tempdir(), "consort.dot"), engine = "dot")

# Rasterized DOT output (.svg, .png, .pdf) requires the Graphviz 'dot'
# binary on the system PATH.
if (nzchar(Sys.which("dot"))) {
  flowsave(flow, file.path(tempdir(), "consort.svg"), engine = "dot")

  # DOT engine with Times typography for serif environments.
  flowsave(flow, file.path(tempdir(), "consort_times.svg"), engine = "dot",
           font_family = "Times-Roman",
           sans_serif  = FALSE)
}
# }