GoFish Graphics
Internals

Graphic Design ​

The third tradition GoFish blends in is graphic design — the craft of making a chart that is not merely correct but good. A chart can plot every number faithfully and still fail to communicate. Graphic design is what closes that gap, and GoFish treats it as a first-class concern, not a layer of polish applied at the end.

Three pieces of that craft shape GoFish most: Gestalt principles, color, and typography.

Gestalt principles ​

The Gestalt principles describe how the visual system groups what it sees — elements placed close together (proximity), elements that look alike (similarity), elements inside a shared boundary (common region), elements joined by a line (connectedness). They are not decoration. They are the mechanism by which a reader perceives any structure in a chart at all.

This is where graphic design and UI component frameworks meet. GoFish's graphical operators are, quite directly, Gestalt principles turned into composition primitives: spread is proximity and uniform density, stack is alignment, enclose is common region, connect and arrow are connectedness. Composing a chart in GoFish is composing it out of Gestalt relations. Bluefish made this correspondence explicit — its relational standard library is drawn straight from the Gestalt relations — and GoFish carries it forward.

Color ​

In data visualization, color is above all a tool for emphasis — for steering the reader's attention to the few things that matter. And the most important color is gray. A well-designed chart is mostly grays, with saturated color spent sparingly, only where the eye should land.

Most visualization libraries do not center gray. They hand you a categorical palette and encourage you to color everything — which spends the reader's attention evenly and so emphasizes nothing. GoFish treats gray as the default and color as a deliberate act of emphasis. Datawrapper's How to use color to emphasize is the clearest short statement of this approach.

This is the design-craft companion to the PL essay's point about color. That essay argues GoFish should not restrict you to perceptually optimal palettes; this one argues that, given the freedom, the well-designed use of color is mostly restraint. See Color Scale Resolution for the mechanism.

Typography ​

Typography matters as much as color, and it is the most underdeveloped part of visualization tooling — GoFish's own included. Here it is a stated direction more than a finished feature.

The intent has three parts:

  • Semantic type, not raw point sizes. Following SwiftUI's lead, text should be sized by role — a title, a label, a caption — with a theme deciding the actual measurements. This is one piece of a broader move toward theming.
  • Labels as first-class. In most visualization libraries a label — a piece of text annotating a mark — is an afterthought, or absent entirely. In GoFish, labels are a central part of the system; see Labels.
  • Attention to detail. The fine craft of setting text — Jost Hochuli's Detail in Typography is the touchstone — is something charts almost never get right, and GoFish wants to.

Sources ​

  • How to use color to emphasize — Datawrapper, on color, emphasis, and the centrality of gray.
  • Detail in Typography — Jost Hochuli, on the micro-craft of setting text.
  • Building Science Graphics — Jen Christiansen, on the craft of explanatory data graphics.