NEWS
gghalftone 0.1.0
with_halftone() screens the fill of any layer at draw time, on a lattice whose pitch is in millimetres, so a figure saved at 89 mm and at 183 mm gets the same screen. The tone profile follows the geometry: flat for bars, areas, polygons and maps, the likelihood of the estimate for intervals, a soft vignette for densities.halftone_plot() screens a whole plot, or a patchwork, in one call. It screens the filled layers, haloes the lines and points that sit over a screen, and adds the theme modifier. A geom it does not recognise draws exactly as it did before.geom_halftone() screens a gridded field, geom_halftone_cmyk() separates one into four process inks, and geom_spot() draws one tone disc per point.with_halo() draws the printer's knockout channel under a line. with_relief() implements illuminated contours (Tanaka 1950).- The
screen aesthetic maps a discrete variable to a lattice angle, a dot shape and a hatch angle, through scale_screen_discrete() and scale_screen_manual(). Legend keys run the real screen over a key-sized area rather than re-deriving the panel's arithmetic.
- Line screens, and Bayer, blue-noise and Floyd-Steinberg dithering for quantised tone.
with_press() draws a screen as a press puts it on paper: dot gain, slur, ink bridges, mottle and plate misregistration. Gain is measured on coverage rather than on tone, which is what lets it fill a shadow in. It is off by default and outside the journal register.- No feature is smaller than 0.09 mm, the journal minimum. The floor is held by dithering, so coverage is preserved and light tone becomes sparse minimum dots or broken hairlines.
- Dot shapes now lay down the coverage the lattice says they should. The agg devices rasterise a small filled circle as an inscribed polygon, so a circle printed at 0.903 of its area at the journal pitch while squares and diamonds were exact, and a screen that mixed shapes printed its circles a tenth lighter than their neighbours while encoding the same thing. Vector output is unchanged.
ggsave_journal() writes PDFs through base pdf() rather than cairo_pdf(). It is one of the devices where a small filled circle comes back the size it was asked for, and it needs neither cairo nor X11, which the macOS CRAN build of R has neither of.- Drawing a screen no longer reseeds the caller's session.
blue_noise_matrix() is seeded so the matrix is identical every time, and it now puts the RNG back where it found it.
theme_halftone() is a modifier rather than a complete theme: paper ground, no gridlines, screen-sized legend keys, the ink palette, and the geom accent. ggsave_journal() writes PNG, TIFF or vector PDF at a column width. halftone_proof() renders at final size plus a magnified crop.km_steps(), km_censor() and km_risk() turn a survfit object into the frames these layers want.