Terminal Output

The --terminal flag renders any plot directly in the terminal using Unicode braille characters, block fills, and ANSI 24-bit colour. No display, no file, no system dependencies — just a UTF-8 terminal.

This is especially useful on HPC clusters, remote servers, or any environment where opening an SVG or PNG is inconvenient.

Usage

# Auto-detect terminal size
kuva scatter data.tsv --x x --y y --terminal

# Explicit dimensions (useful in scripts or multiplexers)
kuva bar counts.tsv --label-col gene --value-col count --terminal --term-width 120 --term-height 40

# Pipe from stdin
cat gwas.tsv | kuva manhattan --chr-col chr --pvalue-col pvalue --terminal

--terminal is mutually exclusive with -o. When both are absent, output defaults to SVG on stdout.

Flags

Terminal dimensions are auto-detected via ioctl(TIOCGWINSZ) and fall back to 100×30 if detection fails. Override with --term-width / --term-height — useful inside tmux panes, CI logs, or when piping output.

How it works

Each character cell maps to a 2×4 braille dot grid, giving an effective pixel resolution of (cols×2) × (rows×4). Three rendering layers are composited on output, with text taking priority over braille:

Colour is output as ANSI 24-bit escape codes. All SVG path types are supported including cubic Bézier curves (tessellated to 20 segments) and filled polygons (scanline even-odd fill in braille space) — so Sankey ribbons, Chord arcs, Pie slices, and Contour fills all render correctly.

Examples

Scatter

Manhattan

Sankey

Contour

Candlestick

Supported plot types

All subcommands support --terminal except upset.