Frame: Axes and Colorbar

frame configures the axes of a figure: labels, limits, scales, ticks, annotations, and the colorbar. It sits next to style (which picks the layout card) and layers (which draw).

frame:
  ax:                          # the main rectangular axis
    labels: {x: "$x$", y: "$y$"}
    xlim: [0, 5]
    ylim: [0, 5]
    xscale: linear
    yscale: linear
  axc:                         # the colorbar axis (with *cmap style cards)
    label: {ylabel: "$\\log\\mathcal{L}$"}
    color: {cmap: jarvis_rainbow2_r, vmin: -50, vmax: 0}

For a multi-panel card, configure each panel under its id (ax0, ax1, …) instead of ax.

`frame.ax` — the main axis

Key	Example	Purpose
`labels.x` / `labels.y`	`"$m_A$ [GeV]"`	Axis labels (LaTeX via $...$ )
`xlim` / `ylim`	`[0, 5]`	Axis limits `[min, max]`
`xscale` / `yscale`	`linear` / `log`	Axis scale
`ticks`	see below	Tick direction/length/width
`text`	see below	Free-floating annotations

Ticks

ax:
  ticks:
    major: {direction: in, length: 4, width: 0.5}
    minor: {direction: in, length: 2}

direction is in or out. Most defaults come from the style card; override only what you need.

Text annotations

ax:
  text:
    - x: 0.75
      y: 1.0
      s: "EWMSSM"
      ha: right              # left | center | right
      va: bottom             # top | center | bottom
      fontsize: x-small      # xx-small … xx-large, or a number
      fontfamily: STIXGeneral
      transform: true        # true = axes fraction (0–1); false = data coordinates

With transform: true, x/y are axes fractions (0–1), so (0, 0) is the lower-left corner and (1, 1) the upper-right — convenient for captions independent of the data range.

`frame.axc` — the colorbar

The colorbar axis exists when the style card is a *cmap variant. A layer attaches to it via colorbar: axc.

axc:
  label:
    ylabel: "posterior density"   # for a vertical colorbar
    # xlabel: "..."               # for a horizontal colorbar
  color:
    cmap: jarvis_rainbow2_r
    scale: linear                 # linear | log
    vmin: 0
    vmax: 0.8                     # or `auto`

Key	Purpose
`label.ylabel`	Label for a vertical colorbar
`label.xlabel`	Label for a horizontal colorbar
`color.cmap`	Colormap name — see Plot Methods → Colormaps
`color.scale`	Color normalization: `linear` or `log`
`color.vmin` / `color.vmax`	Color range; `auto` lets the data decide

ℹ️ frame.axc.color vs layer.style The color range can be set on the colorbar axis (frame.axc.color) or per layer (style.cmap / style.vmin / style.vmax). Setting it on axc keeps every layer that shares the colorbar consistent; setting it on the layer is local. Avoid specifying both for the same mappable.

Ternary axes (`axtri`)

Choose a Ternary style-card variant to get a triangular axis with id axtri. Its three sides are configured with left / right / bottom labels:

style: [a4paper_2x1, TernaryCmap]
frame:
  axtri:
    labels: {left: "A", bottom: "B", right: "C"}
  axc:
    label: {ylabel: "$Z$"}

Ternary layers map data with left / right / bottom coordinates (composition inputs) and draw with the tri* methods (tripcolor, tricontour, tricontourf, triplot) or scatter. See Plot Methods.