rect

Draws a rectangle for each data item. The most common mark — bars, stacked bars, mosaic tiles, and waffle cells are all rectangles.

from gofish import chart, spread, rect

chart(seafood).flow(spread(by="lake", dir="x")).mark(rect(h="count")).render(
    w=500, h=300, axes=True
)

Signature

rect(*, x=None, cx=None, x2=None, w=None, em_x=None,
     y=None, cy=None, y2=None, h=None, em_y=None,
     dims=None,
     fill=None, stroke=None, stroke_width=None, opacity=None, filter=None,
     rx=None, ry=None, aspect_ratio=None, key=None) -> Mark

Closed signature — no catch-all **kwargs. An unrecognized keyword raises a TypeError at the call site instead of being accepted and then quietly ignored at render time, which is the class of bug that motivated closing it (see Frontend IR).

Parameters

A rectangle. Box geometry via the shared dims channels.

Option	Type	Default	Description
key	str		Internal per-node key override.
rx	float	0	Corner radius, x.
ry	float	0	Corner radius, y.
aspect_ratio	float		w/h ratio to enforce; the constraining axis wins when both are data-driven.
debug	bool		Dev-only flag: logs this mark's key and datum to the console as it is built. It changes nothing about what is drawn.

Box dimensions

Option	Type	Default	Description
x	int | float | str		Left edge position.
cx	int | float | str		Center x.
x2	int | float | str		Right edge position.
w	int | float | str		Width.
em_x	bool		Embed x in the parent's x space.
y	int | float | str		Start edge on y: the top edge where y reads top-down, the bottom edge where it grows upward.
cy	int | float | str		Center y.
y2	int | float | str		Other y edge position.
h	int | float | str		Height.
em_y	bool		Embed y in the parent's y space.
dims	dict		Box dimensions by axis name: x/y, or a name the enclosing coordinate space declares (polar theta/r, geo lon/lat). Each value is a position (like x) or an interval {min, center, max, size, embedded}.

Paint

Option	Type	Default	Description
fill	str		Fill color, or a field name for a color scale.
stroke	str		Stroke color. Defaults to fill.
stroke_width	float	0	Stroke width in pixels.
opacity	float	1	Opacity, 0 to 1.
filter	str		Raw SVG filter attribute.

Returns a Mark for use in .mark(). To attach a text label, chain .label(accessor, ...) on the returned mark rather than passing a label option here.

Axis names

x, y, w, and h mean the first and second axis in any coordinate space. Under polar that is the angle and the radius.

To use the names a coordinate space gives its axes, pass them in the dims dict. Each key is an axis name, and each value is either a position (like x) or a dict with any of "min", "center", "max", "size", and "embedded":

# Inside polar(): the same wedge as rect(w=0.4, h="value")
rect(dims={"theta": {"size": 0.4}, "r": {"size": "value"}})

"x" and "y" are always valid keys too. A name the enclosing coordinate space does not declare raises an error that lists the ones it does, and setting the same part of an axis twice (for example w and dims["theta"]["size"]) is an error. dims is the one keyword for axis names, so the rest of the signature stays closed. The same keyword works on ellipse, petal, text, image, and layer.

Encoding

Each option takes a constant or a field name (a string column in your data):

rect(h="count", fill="species")  # height and color from fields
rect(h="count", fill="#4e79a7")  # height from data, constant color
rect(w=20, h="count")            # constant width, data-driven height

Examples

# Stacked bars
chart(seafood).flow(
    spread(by="lake", dir="x"),
    stack(by="species", dir="y"),
).mark(rect(h="count", fill="species"))

# Rounded, outlined tiles
chart(data).mark(rect(h="count", rx=4, stroke="white", stroke_width=2))