GoFish Graphics
Internals

table ​

Groups data by two fields and lays the groups out in a 2D grid — one axis per field. The primary operator for heatmaps and other grid-based visualizations.

python
from gofish import chart, table, rect, gradient

chart(data, color=gradient(["#ffffcc", "#fd8d3c", "#bd0026"]), axes=True).flow(
    table(by={"x": "hour", "y": "day"}, spacing=4)
).mark(rect(fill="value")).render(w=500, h=300)

Signature ​

python
table(*, by, **options) -> Operator

Parameters ​

Arrange cells in a numCols-wide grid (or a {x, y} keyed grid via by).

OptionTypeDefaultDescription
bydictRequired. Grouping fields for the column/row keys — the table operator can't run without both.
spacingfloat | tuple0Cell gap: a single number for both axes, or [x, y].
num_colsfloatExplicit column count (falls back to the number of distinct column keys).

Returns an Operator for use inside .flow().

Examples ​

python
# Heatmap: hour on x, day on y, colored by value
chart(data, color=gradient(["#ffffcc", "#fd8d3c", "#bd0026"])).flow(
    table(by={"x": "hour", "y": "day"}, spacing=4)
).mark(rect(fill="value"))

# Asymmetric spacing
chart(data).flow(table(by={"x": "col", "y": "row"}, spacing=(2, 8)))

Notes ​

  • Data insertion order determines column and row ordering. Sort your data first if you need a specific order.
  • Unlike nested spread calls, table exposes ordinal axes on both dimensions, so axis labels render on x and y.
  • Pair gradient() on the chart color option with fill="fieldName" on the mark for heatmap coloring.

Cell sizing ​

Tracks size by one rule: a column (or row) is as wide (or tall) as its widest (or tallest) cell — track = max(cell size claims). Cells that carry no size claim ("fill" cells, like a plain rect(fill=...) in a heatmap) contribute nothing, so an all-fill table divides its box into equal tracks exactly as before — heatmaps are unchanged. When cells DO carry a size claim (for example a nested chart with intrinsic content size), each track sizes to its widest cell and the table shrinks to fit its content instead of stretching every cell to an equal share of the box.