kuva quiver
Quiver plot — 2-D vector field rendered as arrows. Each row is one arrow with a tail at (x, y) and a vector (u, v).
Input: one row per arrow with four numeric columns: tail x, tail y, u-component, v-component.
| Flag | Default | Description |
|---|---|---|
--x-col <COL> | 0 | Tail X column (0-based index or header name) |
--y-col <COL> | 1 | Tail Y column |
--u-col <COL> | 2 | Vector x-component column |
--v-col <COL> | 3 | Vector y-component column |
--color <CSS> | steelblue | Arrow color (ignored when --colormap is set) |
--arrow-scale <F> | — | Pin the multiplier applied to (u, v) before axis mapping. Disables auto-scaling |
--auto-scale <F> | 0.9 | Fraction of the nearest-neighbor distance used for the longest arrow (the auto-scale heuristic sizes arrows to ~one grid cell). Auto-scaling is on by default; pass this flag only to change the fraction. Mutually exclusive with --arrow-scale |
--shaft-width <PX> | 1.2 | Shaft stroke width |
--head-length <PX> | proportional | Pin head length (pixels). Default: 28% of shaft, clamped to 4–14 px |
--head-width <PX> | proportional | Pin head half-width (pixels) |
--tight-bounds | off | Derive axis bounds from arrow tails only (arrows may overflow) |
--colormap <NAME> | — | Color arrows by magnitude. Triggers automatic colorbar rendering |
--colorbar-label <TXT> | — | Label shown next to the colorbar |
--pivot <MODE> | tail | Where (x, y) sits on each arrow: tail, middle, tip |
--legend <TXT> | — | Legend entry label |
# Zero config — auto-scaling picks a sensible arrow length.
kuva quiver field.tsv \
--title "Velocity Field" --x-label "x" --y-label "y"
# Color by magnitude with a viridis colorbar
kuva quiver field.tsv --colormap viridis --colorbar-label "Speed"
# Tighter field (longer arrows fill the plot) + tails-only axis bounds.
kuva quiver field.tsv --auto-scale 0.95 --tight-bounds
# Pick columns by name
kuva quiver field.tsv \
--x-col lon --y-col lat --u-col wind_u --v-col wind_v
See also: Shared flags — output, appearance, axes.